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Discussion Starter · #1 ·
This is my first build. Here is what I have planned.

Vehicle- 1980 300CD w123 body

Motor- tesla large drive unit in the rear replacing the dif, keeping the stock independent suspension, custom axles to mate to stock hubs

Batteries- 2 full volt packs

Charger- Volt

DC DC conv- Volt

Motor controller- I was going to order EVBMW but they are out of stock, might go with 057 or stealth ev instead

Charger and DCDC controller- thunderstruck EVCC

Bat heater- Volt

Coolant pump- Volt

Coolant valve (if needed)- Volt

Electric Vac pump- not sure

Electric PS pump- not sure

my only ? thus far is the BMS controller. I have a full Chevy Volt BMS with the pack but can't find anyone who makes a CAN that will interpret and send info to the EVCC. Any suggestions are appreciated.

So far I bought a salvage Chevy volt at auction for $2500 and have taken all the components and wiring harness off (as well as lots of other Volt parts). The battery tests good, full voltage. Working on making a test board with all the charging and 12V components to get that working before ordering the motor.

I have a full auto mechanic shop, metal working tools etc. Good at wiring, not savy at coding/CAN (yet?).
 

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How do you plan to control all those Volt components? As you've noticed with the BMS, these proprietary parts have to be hacked and programmed. I'm not that familiar with the Volt, but I believe that is true of every other component as well (although something like a coolant pump can at least be easily made to turn on and off). My expectation is that they're all controlled by a secret CAN bus protocol, and that none of them will work unless hooked up to a computer that understands them.
 

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Discussion Starter · #3 ·
For the bms, the simpbms will read Volt slaves.
For the dcdc and charger, the thunderstruck EVCC will talk with those.

As for the coolant pump and coolant heater, I won't be able to use the stock CAN commands to turn them on and off. Since I have an entire car and the parts were essentially a bonus with the battery pack, dcdc, and charger, I figured I would open them up and see if I could rework the internals so that I could direct wire the 12v or 360V connections needed to make them run directly. I have nothing to lose if I can't. If I can, then I could control the on/off with an external relay. In the case of the heater, maybe have a temp sensor trigger the external relay along with a 12V from the charger on state. For the coolant pump, that would be on with charging and ignition.

This is my first time experimenting with any of these devices, but I've installed aftermarket controllers and added relay systems to vehicles in the past so I'm familiar with the theory. I don't know coding or CAN commands yet so that's where I will be getting an education.
 

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Discussion Starter · #4 ·
Thought I would give an update-

I've got all of my parts minus the electric vac and ps pumps. I setup a test board for everything and thus far got my bms to give a full chevy volt pack readout on the laptop. I also got my Volt charger to wake up and start charging my first Volt pack. I figured out how to get the Volt coolant pump to come on so now I can also use that.

When I get another run of time I will plumb my coolant system so I can get the charger to run a full cycle and start mounting my tesla motor to a board and wire up the high voltage contactors, DNR switch, and precharge resistor circuit to test those components.

Then it's on to stripping the car!
 

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Discussion Starter · #5 ·
Here's an update. -

After a setback with the Tesla motor controller on the test bench, I got the charging system charging and the motor spinning.

I stripped the 300D and started making battery tray mounting.

I'm using two complete Volt packs.
A full pack will go in an aluminum battery box under the hood where the motor used to be. The smallest of the three batteries will go in the transmission tunnel. The two larger batteries will mount where the fuel tank used to be (between the rear seat and trunk). It creeps a little into the truck space, but still leaves a good amount of room for a usable trunk.

Depending how the box spacing works out, I'm going to mount by EVCC and BMS's inside the box in their own protective boxes inside the battery box. It would be nice to mount the charger and the contactor box to the outside of the battery box and have everything prewired so it just drops in and just has to have signal, HV, and coolant lines connected.

I'm mounting the DCDC to the space where the radiator was and putting a small 12V fan on it. I got a large oil cooler to use with the stock electric fan next to the DCDC for battery and motor coolant system.

For the PS and vac pumps I harvested some from a Volvo in the junkyard 50 ft from our shop. Got to get the harnesses and mounting for both as well.

I'm going to concentrate on mounting all the components first and then order wire and coolant hoses when I can get a visual on the lengths and direction.

If you are interested I'm posting progress on Instagram - @davesautowizard
 

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Hi wigman
If you have a complete salvage Volt why not use the Volt drive train in your build? Are you building a high performance car?

Cheers
Tyler
 

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Discussion Starter · #7 ·
Yes, I wanted to build something faster than the Volt. Also, I don't have a standalone controller for the Volt motor and since there is an ICE motor integrated, it wouldn't be possible to just transfer the computer modules without reprogramming them.
 

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Sorry, I was thinking about the electric one, Bolt? Or a Leaf. The motors can do a lot more than factory spec so don't dismiss them. A d if the moor burns out, they're cheap as chips so just drop another in... Plus the smaller packaging is really helpful for an ICE conversion.

Cheers
Tyler
 

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I agree that the Bolt drive unit is an appealing choice: it is compact, and rated by GM in the Bolt at 150 kW. The W123 300D engine is only rated at 65 kW (87 hp), so while the performance potential of the Bolt motor with stock controller would not match a large Tesla Model S drive unit, it would likely be an improvement over the original engine in the Mercedes.
 

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Discussion Starter · #10 ·
Just a little update-

I built all the mounting brackets and battery box and then stripped the car again.

I painted the engine bay and all the brackets and remounted everything with final hardware.

Then I ran all the coolant lines and connections and built manifolds off the radiators for fan switches and a temp sensor.

Next I started wiring from the back of the car to the front. The driveshaft tunnel made for a nice space for the coolant hoses, hv cables, and wiring harnesses. I ended up using electric plastic hard conduit for the hv lines so they had extra protection.

Currently, I still have to wire up the fans, coolant pumps, and dash board and then I’m ready to test my low voltage System.

I ended up building a HV and 12v control box with a divider in the middle. The box houses a bms for each battery pack, the charge controller, a relay bank for fans, pumps, etc, hv contactors, precharge circuit, shunt, and all the fuses from the main motor fuse to a bank of 12v fuses. Putting everything in the same box and wiring it before going into the car saved a Lot of connections. The box has a 31 pin connector for 12v signal and low amp connections and a 6 pin connector for the pumps and fans (higher amp draw). Those are quick connect weather proof plug harnesses. The relay and 12v fuse bank I harvested from a junk sprinter van I have.

Before wiring, I made a large spreadsheet with my PIN numbers and component destinations. I used a label maker for all the harnesses so when I was making all the connections I Didn’t have to think about what wire was going where. The label maker and chart made things infinitely easier.

I wanted to use my stock gear selector instead of push button shifting so I repurposed the original neutral safety switch that controlled the reverse lights and neutral/park start. I had to make a custom bracket and cut down the linkage since there was no longer a transmission to mount to. It was easy to get 12v in park and reverse, but there was no signal to drive. I hooked up a 5 pin relay and connected the trigger wire to both the 12v from reverse and park. That way the relay is always on In either park or reverse. The 12v passing through the relay comes out the pin that is connected to the Input when the relay is in the off position. No park and no reverse turn the relay off sending 12v to Drive. The only issue was that park and reverse were then connected together since they were both hooked to the relay signal wire. I put two diodes inline to prevent the backfklow of current so only one gear would be selected at a time.

To accommodate for the weight differences I installed an adjustable coil and shock suspension. After the wiring is done, while I’m waiting for my axles, I’m going to drop the car and set the ride height.

That’s about all for now. Both battery packs are live up to my master disconnect on the battery box and no sparks!

I’m doing photo updates on @davesautowizard instagram And plan on making a YouTube when it’s finished
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Discussion Starter · #11 ·
So, I’m pretty much finished. It runs and drives correctly as of last night.

you can check out the first drive video at @davesautowizard on instagram

Pro tip- my last obstacle was bleeding the coolant system on the motor side. I thought it was bled because everything was lower than the reservoir but when I got derated and stalled from the inverter safety feature and had an ice cold radiator I realized it was not. I did the same thing I did on the battery side. I found a spot to put in a t fitting with a ball valve. Hooked up a line to the valve that went 3 ft above the highest point on the system and hooked up a brake bleeder pump. Then I turned on the electric pump and pulled vacuum on the line. The reservoir gurgled and went down. Shut the ball valve and lock it until next time it’s needed. Now my radiator is warm to the touch after a hard run up an incline.
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