Bolted On



I’m thoroughly enjoying the CAN/Arduino aspects of EVTV these days.  I can quickly edit a source file and compile it to a small Arduino board in about 20 seconds from any  Mac OSX machine in the shop or at home.  I can e-mail those files to myself or thumbdrive em to get back and forth.  In short, I’m in my element.  It all makes sense to me and even has a sort of sense of order that brings a calm to an otherwise chaos enfolded existence.

But from our first EV build, I have been mystified by the simple act of connecting an electric motor to a car. And to this day, contemplating any build causes a little anxiety level over just how we are going to connect THAT motor to THAT car.

It always works out.  Indeed, it always works out well.  We’ve never really had a problem with vibration or with it coming loose.  I guess the worst we’ve done was the Mini-Cooper and it really wasn’t about mating the motor to the transmission.  The right hand half shaft had a bearing on it that was supposed to be supported by the engine, but we didn’t have an engine.  We kind of fabbed up a sling around the motor with a holder for it, but the shaft kept popping out.  Finally solved it with a bit sturdier steel version.

The Mini Cooper sits idle today.  We blew up the DC-DC converter and possibly the Rhinehart controller we had adapted to the MES-DEA motor.  That system had actually worked pretty well, but contemplating fixing it now leads me to a lot of changes to the cooling system, the DC-DC converter of course, but if we are going to do all that, we might as well put in one of our Siemens or UQM power plants for a bit more power and all the configuration advantages of the GEVCU.  And so the repair becomes an upgrade and the upgrade almost goes to a reconversion and so the Mini Cooper sits.

Our first EV was a VW transmission in the replica 1957 Porsche Speedster.  We originally used a bulky cast aluminum adapter availabe from CanadianEV.  Later we replaced it with a bit sleeker version from Thunderstruck.  We liked the Coupler from Canadian EV and the adapter plate from Thunderstruck and eventually developed our own kind of combo.  Later EVNETICS came out with a really deluxe bling looking adapter for the VW and we ordered from them for several years.  Unfortunately, they are no more.

So it always gets worked out.  We even married a Husted twin 11 inch to the Escalade six speed transmission flex plate and somehow shimmed it in there where it worked perfectly. But almost always there are others involved in the actual design of the connection.

The truth is that I’m not at all mechanically inclined and indeed I’m baffled by the assembly instructions that come with a baseball bat.  We’re trying to put a two post lift together in the shop right now and it is just mystifying to me.

In the past couple of years, we have been doing some great things I think with the Siemens and UQM motors.  Each have an identical 26 spline very short shaft on them designed to marry to an eGearDrive.  We had bought 16 of these drives at the Azure auction, and have since reordered in a minimum order quantity of 20 five or six times.  They’ve sold well.  But I confess I’ve never actually used one in anger or installed one on a car.

The nice thing about them is the UQM or Siemens motor just bolts right to it and the shaft is connected with an eggregiously simple 4 inch long “coupler” that simply fits over the motor shaft on one end and the gearbox input shaft on the other.  This makes the motor/car interface extremely simple.

Or does it?

Actually, it kind of moves the problem.  Now you have to have half shafts – axles to connect the gearbox OUTPUT to the wheels.  Another version of the same problem.

Please do NOT send me the dozen links you can easily find for people who make custom shafts.  They don’t actually.  Yes, I know what the web site home page says.  They specifically TOUT their custom axle work in all cases.  But what we’ve found is that if you call them, they don’t actually DO that anymore.  Too much work.  Easier to just ship off the shelf assemblies – you do have a part number don’t you?  You DO know what you want to order don’t you?

So when Brian Couchene offered to do a video on how to do all this, I jumped at it.  Indeed I could hardly wait to see it.  Perhaps it is again my mechanislexia.  But after watching it, I kind of had the idea that I had just watched him present a total of FOUR strategies he more or less guaranteed would NOT work to get you a shaft built???  Or???

[jwplayer streamer=”rtmp://” provider=”rtmp” file=”news082815-iPhone.mp4″ hd.file=”news082815-1280.mp4″ image=””  width=”850″ height=”522″ html5_file=”″]

Of course, for many cars you wouldn’t use the gearbox but adapt the motor to the transmission.  Again, we had had EVNETICS do an adapter for us to mate the Siemens motor to a VW transmission.

We had a local machinist make us kind of a different version of that for the UQM to VW used in the Green Thing.  And so we kind of stumble along getting by from vehicle to vehicle.

We’ve kind of adapted a Matt Hauber design that Ed Clausen used on his BMW.  This is kind of a coupler “blank” that is a bit too small for the UQM or Siemens shaft.  You heat it up to 400 degrees F for an hour in an oven and then slide it on. When it cools, it shrinks and becomes rather tightly bound to the shaft.  We carry those in a three inch, four inch, and five inch diameter now.

Adapter plates are somewhat easier to design and build.  But again it is mechanical.

I’ve simply assumed that someone somewhere would set up an EV machine shop to do these sort of things.  But it really hasn’t emerged.  There are just two many cars and too many configurations.  So I STILL contemplate any conversion with a certain amount of anxiety over the motor/machine interface.

One of our many sort of stalled projects here at EVTV is the Aristocraft boat.  I actually had some ideas originally about how to drive it.  But Jeff Southern, truly a master of machine work, offered to do it for us.  After having the boat nearly a year, he dropped it off at the shop a month or so ago untouched.  He just hadn’t had time to do anything with it.  And so there it sits.

The Tesla Model S drive unit has been a kick.  I guess I suffer from a touch of Tesla Awe myself and expected to be at the CAN thing until the end of the year.  Basically we have it running from a $99 Arduino Due clone we make.  It just works.  I’ve got full control of the drive train and really quite good information from the inverter.  I have two strategies for a human interface – the EVIC and a new CAN switch module Collin found in Italy, but which is actually made here in the U.S., the Powerkey Pro 2400.

But it puts us right back with the eGearDrive axle problem.  We have to determine how to connect a shaft from the single speed gearbox to the wheels of car number whatever.  But unlike the Siemens and UQM, there is no good way to separate this highly integrated drive train into components.  You kind of have to use it as it is.  And that means an Independent Rear Suspension or IRS setup.

One viewer pointed us to Art Morrison Enterprises.  Again, this LOOKS like a custom suspension shop but it simply isn’t.  They’ve got a few stock items, and you can have those in any color you like as long as it is shiny.  They actually make a kind of a generic IRS they call the multilink IRS.  But when we contacted them about adapting it to the Tesla drive unit, they immediately declined.  For $10,400 we can buy their off the shelf unit and do whatever we like with it.  And they basically stand behind their work.  They pretty much guarantee it will NOT work with whatever you want to use it for and you probably shouldn’t be trying to do that anyway.

The salvage world is actually kind of strange.  We THINK we’ve bought a Tesla Drive unit with the complete rear clip – cradle and shafts and all.  But he isnt’ going to ship it to us until the end of September.  That might give us some ideas.  One strategy is not to try to adapt the shafts to the wheels on the car, but replace the whole assembly and use the Tesla wheels.

The other sits right next to the TEsla Drive Unit Test Bench – the 1990 VW Vanagon pickup DoppelKabine we bought from Otmar a year or so ago.  We had several adventures painting this vehicle but finally got it covered in bright yellow plasti-dip.

The Vanagon is interesting in that it already has an IRS rear end.  More, the axles on this are very different.  Instead of terminating at the transmission with a splined shaft, it actually has a 100 mm flange with six bolts that bolts to a similar flange on the transmission.  It might be very easy to take the CV joints we have inserted into the drive unit on the bench, and kind of build them up to a similar 100mm flange and just bolt it together.  We’d have to take care to make sure it wound up being as thick as the transmission so the VW shafts would be the correct length, but it could be an easy fix.

I’m trying to picture how I feel about screaming down the road, seated right up in the extreme front of the vehicle just behind the windshield, with a Tesla Drive Unit accelerating me to just under the speed of light, with VW steering and a very high center of gravity.  But it would be one smokin DOKA.  And I wouldn’t have to move the drive unit very far.

Fortunately, this all seems to be mostly a Jack problem.  We’ve sold a lot of Siemens and UQM motors and rarely even hear how they adapted them to the car.  Apparently with little difficulty.  And as I have said, we have sold a lot of eGearDrives, many without a motor at all, so that appears to offer a popular solution to something.

The weather has been just gorgeous here recently – we had a week in the high seventies with sunshine.  I’ve been driving the yellow thing, and I still don’t get over it.  We did replace the shock absorbers on the left side.  I don’t know why they went out with the shocks on the right side doing fine.  And indeed we repacked the grease in a CV joint in the right hand drive axle and that quited an annoying knocking sound.  But I truly never get over it.  Mathieur Rech contributed just a short video of his Toyota Land Cruiser padding about through the countryside in near silence.  And so it goes with my 1974 VW Thing.  It is just very quiet.  Squeeks from the seat springs.  Which appear to have some mysterious connection to the left side shock absorbers.  But that is all the noise it makes.  When it gets up to temperature a heat exchanger fan kicks in and provides a vague whir.  But I basically glide around Cape Girardeau in very near silence.  And I take unusually perfected joy in doing that.  Cars and trucks are roaring and snorting all around me, but my car just doesn’t make any noise.

I’ve also become a huge fan of regenerative braking.  As we demonstrated rather empirically years ago, it doesn’t add in efficiency to anything even approaching its reputation.  But it does FEEL good.  Both in the Model S and the Thing, it gives you a sense of total control with your big toe.  You can just make the car do anything you want almost by thinking about it.  And then it does it silently.  This is so very different from any pre-electric driving experience I ever had, that I just never do get over it.  It alters your senses and your sense of the road surface and what is going on around you.

Jack Rickard

















42 thoughts on “Bolted On”

  1. I’m as far from you as one could be in the EV sphere. The mechanicals are the simple part in my opinion. It’s the programming that baffles me. I do possess the ability to load files on a thumb drive but that’s where my programming skills end. We have been testing the Electrod on the road the last few days and I am loving the regenerative braking as well. Definite EV grin. Very much looking forward to Evvcon and getting my nose in some half finished projects,

  2. The response from No Limit Engineering in Tenessee was a bit more positive than Art Morrison. Perhaps reach out to them as the initial response I got from them showed an interest in this project.

    As I was looking online at pictures of various IRS setups on different OEM cars, including the Models S, the idea of transplanting the entire Tesla rear subframe with drivetrain, suspension and wheels occured to me also. Of course Ottmar was planning on putting the entire car under the stretch VW van.

    When I started comparing the rear track width for the Model S (66.9 inches) versus most cars at 50-63 inches I realized it would require large fender flares or custom offset wheels. I believe the VW Doka is around 62 inches rear track width.
    A new F150 rear track is around 67.6 inches and would readily accommodate the width.
    See how smart I can type myself up to. Just don’t ask me to write code unless you want it going toghether about as well as your new lift.

  3. I am evaluating my options for my RX8 conversion, and one of the major issues I see with grabing a Tesla motor plus subframe onto a donor car are:

    * how it would affect vehicle dynamics – ot could be a major depriment as vehicle chassis, especially modern ones, are finely ballanced. Having a tail swing out, or the car dramatically scrub understeer would be a bad result, and….
    * Here in Australia we must get engineers reports to inspections to ensure a vehicle has been modified safely. Basically replacing the entire rear suspension, modifying the body (for the struts/coils) could well turn out to be a multi-thousand dollar excursion, and potentially even more if further refinement is required.

    Due to the above, as much as I love the idea of using a Tesla power plant, I think I will be looking at mounting motor to gearbox. However that motor may end up being a Nissan Leaf one….. it actually has good specs. On that front I discovered that the Nissan Leaf motor has a peak power output that is not shown in its specs. I only cottened on to it when calculating acceleration energy/times. I discovered that it can potentially deliver around 108kW for short peak bursts, with I guess a respective increase in torque to.

    So for me at this time learning about canbus signals in/around a Nissan Leaf is becoming more important as I go down this path. I dont expect Jack and the team to start digging down that path just for me, however I think that in the next few months I may be giving the team some input along this front.

    Fun times ahead 😉

    1. I gather we have some pretty restrictive regs here in Aus. I believe that includes having a clutch or mechanical disconnection of motor and wheels. This makes motor to gearbox conversions about the only solution I can see. It doesn’t stop me thinking about a Tesla transplant into a big old Valiant though… I’d love to go cruising in an electric land yacht.
      I can’t wait to hear how you go with the RX8.

  4. The left side of the Thing is the driver’s side, isn’t it? If you rarely take passengers, that would explain the left side shocks wearing out faster.

    I’m with Chris Carlson too- the mechanical side is the straightforward part for me. I watch your programming and CAN efforts with awe.

    1. Stanley A. Cloyd

      I just closed the shop for the night. Jack and the full metal jackets get drunk, play with high voltage, and go for a drive. As I quaff yet another beer I realize I’m but yet another wanna-bee in the larval stage. I get drunk play with high temperatures ( up to 3,000 F ) and pour castings with molten metal. Even if I pour an EV adapter before EVCCON, I won’t have the ability to final machine it until a week after EVCCON. Boo-Hiss. yet another year as a spectator rather than a co-hostage.

  5. Looks like Jack thinks the only option with the TESLA Model S drive train is to leave it as is and make it an independent rear suspension driver. So be it. With several of you bloggers inquiries into AME it seems as though they are not interested in making the TESLA Model S I.R.S. as a product option, and modifying their existing $10K plus product to me seems like a non- starter.
    There is a huge up front engineering cost in designing a I.R.S. for a myriad of vehicles using the TESLA Model S drive-train. The design would have to account for various track widths , which would mean custom half-shafts to various spindles for the control arms, disk brakes,to hubs that would accommodate the vehicles wheels and more.
    I did a search on “independent rear suspension design” and I came up with the following link . It seems from his web-page that he would handle all the particulars in making the TESLA Model S drive train work in your vehicle. It is up to you to inquire.
    Mark Yormark

  6. Yet another NiMH mignon (AA) – trying to set our house on fire.

    Somthing smelled. A peculiar smell, not electronics. I am running our new ventilation system meant for the i-MiEV remote dashboard. It has got the inside of a kitchen ventilator keeping smells and fog from the oven away from the rest of the house. It smells a bit like herbs meant for cooking. Not unpleasant.

    So no alarm rang until I noticed it is not the fan. It must be a lot closer to me. I took that box in my hand and it was hot. The LCD was dead. 3 green lamps meant 3 batteries charged and ready to go back in my camera. The fourth one was still red and charging. I had to use a pair of pliers because I could not touch the battery and it was glued in.

    Cooled it down in the sink with a lot of water and let it dry outside over night. Today it reads 0.7 ohms in one direction and 0.5 in the other. Zero volts.

    Looks like the charger survived except I have to charge one of the AAs using the Bs box now. Even the LCD is working again.

    The smell?

    It smelled like our i-MiEV on the CHAdeMO.

    Peter and Karin

  7. Walking around my cars with a tape measure, which I repeated several times looking in vain for easier results, it seems to me that a Vanagon (DOKA or no) will need about 2″ per side of extra fender flare to reach the outside of the 19″ Tesla tires. The Tesla suspension is pretty tight. I’ve looked in vain for some way to make it narrower without losing tire weight handling capacity. At least the extra flares full of tire should offer a nice “Stance” as well and more stable handling!
    And just to clarify, I will be sectioning and blending various parts of the Tesla under the Vanagon. I’ll certainly retain the Tesla suspension subframes and geometry while getting creative with the upper strut mounts. The battery, I’ve decided, probably wants to mount to rectangular steel tubes rather than the stock aluminum Tesla body.

    As for Vanagon axles with custom inner hubs, I like that idea. does make axles in various and custom lengths to fit a Vanagon (same splines as the bus transaxles used in sand rails.) I know this to actually be true since I ran them with previous transmission conversions. If you go that way, you may want to upgrade to the “930” CV’s with a different bolt pattern since they are stronger.

    In 2009 Rob Moore made custom axles for my Honda Insight to fit the EV-1 motor. I cut and welded the Saturn and Honda axles like this:
    After testing I shipped him the frankenaxle with some clean CV’s so he could duplicate them in heat treated 300M or 4140. I don’t know if he still offers the service. His website is hacked, seems like a phone using type of guy. 619 296 9180
    May be worth a call.

    1. Otmar, why not use the stock Doka suspension and tires? Just mount the Tesla drivetrain and then all you need is custom CV shafts. No fender flares needed. The custom CV shafts could be made by utilizing the inboard joint from the Tesla, and the outboard joint from the VW. Then you would only need a custom splined shaft that mated to the VW joint on one side and the Tesla Joint on the other. This is basically what I was trying to do with the Borg Warner gearbox. The difference being that I didn’t have an inboard CV joint to start with, I had to either machine one or find a compatible one, which I did.

      1. Brian, that’s certainly a viable option that would technically be much easier.
        I’m doing it the hard way since I wanted the air suspension, massive Brembo brakes and the ABS to still function.
        A small but very important corner case is what to do when regen causes wheels to slip. In modern cars the ABS tells the motor to reduce or stop regen. If I were not running the Tesla ABS and Gateway then I’d need to find another way to allow safe regen.
        The custom splined shaft is exactly how I did the Honda that I linked above.
        Fun stuff. Thanks for sharing how you did it!

        1. Otmar, I completely understand, “doing things the hard way”. There are several aspects of my build that I am doing the hard way because that’s how I want it done. If I didn’t want my vehicle custom, exactly the way I want it, then I would have bought an OEM vehicle. I understand your case about locking up the rear wheels, and I understand your desire to have the vehicle the way you want it. In my build I address this situation in two ways. #1, I don’t set (accelerator pedal) regen braking very high. I do set regen braking (brake pedal) higher and use a pressure sensor in the hydraulic brake lines. #2, I place a sign on the dash stating “This vehicle doesn’t have a brain, use yours”. Meaning if you lock up the rear tires by pressing too hard on the brake pedal, it’s assumed that you the driver know enough to let up on the brake pedal.
          There will always be risks with every system, it’s just how much and which ones you want to deal with. On my ICE car, my ABS system is malfunctioning randomly. Every once in a while I press on the brake pedal and the ABS system thinks one wheel is locked up (which it isn’t), so it modulates and reduces braking force, nearly to zero. No matter how hard I press on the brake pedal, I get almost NO brakes, it feels like I’m sliding on black ice in July. The only way to stop is with the parking brake. In this case a failure in the ABS system could CAUSE an accident instead of preventing one. The dealer can’t figure it out because it’s random and the ABS computer isn’t throwing any faults. I’ve had this issue before, and it’s either a corroded ABS wiring connector, intermittent open in the abs wiring, or a bad wheel bearing, the problem is finding it.

          1. I was 45 years old before I drove a car with ABS on it. In snow in Colorado I did find out what that meant and I have to say I found it alarming. So not having an active ABS is not quite the same dire threat to me as to some I suppose.

            Second, my tastes for regen have changed remarkably over the course of the last six years. I originally didn’t have it and learned to drive the Speedster without it, gliding fabulous distances on no power at all and preferred that. On the Mini Cooper we used regen on the brakes only rather than the vacuum booster. A bit of pedal made regen, and if you put some ass in it you had mechanical brakes.

            Today, I generally turn regen way down and front load it on the very front part of a hydraulic pressure sensor for brakes, or disable it on the brakes entirely. But I have come to LOVE regen – on the throttle. And the first full third of throttle travel is now regen sloping from very little at 33% throttle to max regen at about 3% throttle. I can bring the vehicle pretty much to a full stop with regen using my right foot. And I’ve come to love driving that way, and an ice now feels almost totally out of control the whole time I’m driving it now. Even though compression gives you a little backoff when you ease the throttle.

            The Tesla Drive Unit will not have an ABS input normally. We do however have the ability to adust regen in 256 increments and you could certainly employ a paddle shifter or other mechanism allowing you to kick off regen entirely and momentarily.

            In a drive test in the Model S the other day I discovered something a bit alarming. We are trying to decode cruise control. Would you believe at highway speeds if you kick off cruise, you get full regen instantly??? I found that very surprising in a kind of unpleasant/alarming way. The traffic on my bumper were not amused either apparently. Perhaps had I given them their own key fob so they could actually open the hatch before trying to climb in they might not have had to use the tooter so enthusiastically.

            Much is a matter of taste and acclimation. But truly it’s an embarrassment of riches as I can use regen on the throttle to slow down very quickly if I desire, I STILL have a full set of hydraulic brakes if that doesn’t work to suit, and a handbrake in the case of the VW Thing. I’m pretty confident I can get stopped.

            Jack Rickard

  8. Not sure why there isn’t a “Reply” link to your comment, Jack, so I’ll post a new one.

    “In a drive test in the Model S the other day I discovered something a bit alarming. We are trying to decode cruise control. Would you believe at highway speeds if you kick off cruise, you get full regen instantly???”

    I have a 2016 KIA Soul EV+ and discovered the same thing! The only difference is that regen in the Tesla sounds like it is a little stronger than in the Soul EV. They should just program a slow increase in regen when kicking off cruise control unless the brake pedal is touched. I’ve had to learn to push on the throttle a bit before turning off cruise. I wonder what the other OEMs do with this situation.

    David D. Nelson

    1. +1 on the lack of reply link.

      Jack, monitor your motor temp closely. I have found the “driving with one pedal” method quickly heats up the motor during repeated decel maneuvers at 45-55MPH speeds.

      All the best,
      Aaron Lephart

    2. My first car was an NSU Prince 4 with motor in the back. Once I wheeled around a lorry with trailer in the Eiffel mountains. I do not remember how I survived. Around a turn I lost control then came the lorry. I passed the lorry and continued turning. I dont know how I survived, me and the car. That was the only car I could ever get out of a turn.

      Next car (plus one) was I Volkswagen Beetle. Again air cooled. Again motor in the back. Never could I get it back when I lost control and with the beetle I easily lost control.

      Front wheel driven cars were a lot easier. I never lost control in the first place but a Volkswagen Rabbit with ABS was my first and final ICE car that felt like I could drive it in winter.

      The Mitsubishi i-MiEV has got a built in Nanny. It not only controls the breaks but the throttle as well and it controls the breaks individually. It simply denies doing funny things in the snow. It almost drives like a plough. Of coarse it has got a switch to turn the Nanny off but beware it has got the motor in the back.

      No cruise but I can switch regen and I usually keep it agressive. There have been situations when I suddenly needed breaking. Dancing ballet with gas, kludge and breaks is a waste of time when you urgently need it. Breaking when lifting my foot saved me about 2 seconds and saved me from stepping through the floor when hitting the breaks.

      On the other hand there have been situations when meeting the metal with the pedal saved me. Gassers far too often left me starving on a crossing with a stalled engine. That was the end of our final ICE. I am glad I was not the driver nor the owner when that happened.

      Peter and Karin

    3. With the 190SL project I’m doing I added cruise. I have the same problem. When you kick off the cruise it immediately goes from forward power to max regen. This is quite exciting. Luckily, I’m writing all of the code for the ECU so I can make it feather in the regen and not slam on. I would never have imagined that Tesla had not fixed this problem. It’s terribly jarring when it happens.

      1. Seems to be the same with the Ampera so presumably also the Volt. Touch the brake or the disengage button and you have immediate regen. I habitually drive mine in “L” (max regen) rather than “D” (similar-to-ICE-feel regen) so it is quite noticeable. I feather the throttle when disengaging regen to avoid upsetting the passenger’s drinks trolley. An uber-gentle ramp rate would be ideal

        1. Is there a way to make the brake lights come on with the HPEVS/Cutis controller?
          I’ve got my regen set to about 35% which is as much as I dare go without brake lights…I’d like to go much more.

          1. Pin 3 of the main connector is the brake light relay output from the Curtis. I think it automatically activates during regen but I’m unsure how to set the threshold.

            On the GEVCU, we can set a brake light output anytime regen exceeds 10 Newton Meters.

            Jack Rickard

          2. Bill,

            You are referring to the “Brake Light Threshold” setting on p24 of the latest programming instructions for 5.13/5.14 or higher. You do have to have at least 5.13 of the controller firmware for this feature. Then use pin 3 as Jack states, but also combine with the coil return on pin 13 (ie: instead of frame ground) to drive a 12V relay (I used the same make/model relay as for the pre-charge ones) which contacts can then either parallel your pedal’s brake switch, or feed 12V directly to your brake light circuit (I did the latter). You can see the options on 14-16 on the latest 5.13 and higher wiring diagram.

            Hope that helps!

            – Collin

          3. Collin (NorthVan),
            Did you actually get the Regen Brake Light to work properly?
            I’m having some problems.
            It kind of works if the headlights are off. The brakes lights come on during regen but flicker very quickly.
            If the headlights/tail lights are on, the brake lights don’t illuminate at all.
            The settings on the Curtis seem to be ok. I have the Threshold set at 70amp.
            Any thoughts??

            I don’t mean to hijack this post so maybe we should do this via email.


          4. Bill,

            Hmmmm… sounds to me like the problem may be where and possibly how you tapped into your wiring harness for your brake lights?

            What currently happens when you stomp on the brakes — do the brake lights come on normally? Even with the headlights on? What then happens when you manually short the contacts on your brake regen relay, do you get the same behavior as when you hit the brake pedal? If your brake pedal switch works okay, but shorting the relay doesn’t, then I’d suggest having another look at how you are paralleling the pedal switch with the relay.

            For my 911, I was lucky in that in the rear of the car where the controllers and motor are, there was the cruise control unit for the ICE. I bought a used wiring harness for the cruise control for about $40 on eBay (I avoid splicing stock wires where possible), as one of the pins was for detecting the brake light 12V signal. For my brake regen relay, I simply send a 7.5A fused 12V to this pin, and the brake lights come on.

            The other option I considered was having the relay parallel the stock brake light switch, but that is connected to the master cylinder wayyyyy over at the front of the car. I am trying to run as few wires from one end to the car to the other as possible, relying more on CAN bus instead for that purpose, since those 2 CAN wires can replace hundreds of these types of wires and pretty much sums up why it was an inevitable invention in the first place. Good foresight, Bosch. Also kind of ironic since I am adding CAN to a car that never had it in the first place; it’s of the 1989 vintage.

            Good luck!

            – Collin

          5. I tapped directly into the wire going to the brake lights. The lights work with the pedal and if you jump the regen relay.
            I thought it might have something to do with the some sort of voltage coming back into the controller but that’s not possible because the entire lighting circuit is isolated through the relay.
            It might be a voltage thing. With the lights on, the 12v system goes down to 12v instead of 13v. I can’t imagine the controller is that sensitive though.
            I adjusted the Threshold setting from 60amp to 100amp. No change.
            I turned off the regen during braking. No change
            At this point I really have no idea. I’m sure there will be someone at the event-formerly-known-as-EVCCON 2015 will be able to help figure it out.


          6. Hey Bill,

            It could be a “voltage thing” as you state, since my system doesn’t budge below 13.5 volts. I have a 12V battery in parallel with my 800W DC/DC converter (bought from Jack), which seems to keep everything nice and stable. Maybe your DC/DC converter under-powered for your system? Perhaps you could try temporarily jumper-cabling a [well charged] 12V batt to (or bypassing) your DC/DC converter and see if your results change. There’s always the $500 dollar solution: replace your headlights with those LED Trucklites, which I am also considering.

            – Collin

          7. My DCDC converter is definitely dying. If I have my lights on the voltage floats around 12v and when I put the brakes on and the vacuum pump comes on it’ll fall below. If it falls too far the whole thing craps out and the truck dies completely. Not good…
            I put a small 12v in parallel last week but that doesn’t seem to work either.
            I’ll swap out the converter this week if Jack has one lying around and see what effect that has.
            Thank Collin!

  9. Quote from EV World:

    “Air Pollution Responsible for Some 1,6000,000 Deaths in China Annually — That’s what a recent study by Berkley Earth calculates: that’s 17% of all deaths in China. The data comes from China’s national Air Reporting System, which includes 945 sites in 190 cities that report hourly via the Internet. Notes Green Car Congress, which reported on the study:

    “During the period analyzed, 92% of the population of China experienced >120 hours of unhealthy air (as defined by the US EPA standard), and 38% experienced average concentrations that were unhealthy.”

  10. My fellow bloggers, by the title of this “BOLTED ON” , and EVTVME Jack Rickard’s recent success of getting the TESLA Model S drive-train to run without issue, I should be reading in this blog of possible solutions for adapting this exciting said power-train in many high end D.Y.I. builds.
    I can imagine there are individual out there that are hungry to do a build with TESLA Model S and willing to share with the group reasonably priced and well engineered solution to mounting this power-train in an independent rear suspension in a donor vehicle.
    Come on…Let us get excited!
    Mark Yormark

    1. After reading the court’s decision and opinion (, in my layman’s opinion, EVTV could successfully sue Tesla for libel. (Bullys and the BoobTube episode)

      Some particularly interesting comments from the decision:
      * “Fair use in not just excused by the law, it is wholly authorized by the law”
      * “…a copyright holder must consider the existence of fair use before sending a takedown notification…”
      * “…if a copyright holder ignores or neglects our unequivocal holding that it must consider fair use before sending a takedown notification, it is liable for damages…”
      * A person unjustly accused of infringement can pursue recovery of damages for both actual and unquantifiable hurt
      * “It is undisputed that Universal did not consider fair use before sending the takedown notice.”

      Regarding the last statement, I strongly suspect that Universal’s method of identifying alleged infringers is the same as Tesla’s: i.e. searching with Google or within YouTube. Finding something that mentions the word “Tesla” does not mean infringement, something Tesla either ignored or neglected to consider.

  11. Bill,
    I have a small motorcycle battery, 400W DC/DC converter and an automatic battery charger which also charges the 12V aux battery when the main traction pack is being charged. This seems to be the best solution for me. The motorcycle battery works as a sufficient buffer during high drain situations, such as an eletric power assist pump when you try to turn the steering wheel too far, and this way you can get away with a much smaller DC/DC converter.

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