E36 Megasquirt/Painless Chassis Harness Starter Issues

[91ironworker91]

Hi all,
I have been building my 1995 M3 for the last couple years in hopes to one day rally it. The engine is an S50.

A bit of background:

I ripped out every wire BMW put in the car and installed a painless #90501 chassis harness in the car. I also made my own engine harness with the megasquirt diy efi.

How it's connected:

The car is turned on and operated by 3 rocker switches - MAIN -- STARTER(push button) -- FUEL PUMP.

I have the starter switch going to a starter solenoid then to the coil for the starter (IE - where the medium sized stud is where the black/yellow factory wire went). The solenoid gets its power from 2 red wires (Painless #934)

On the main stud on the starter I have BATT (+) and a jumper going to the alternator

Now the final connection is where things get weird. This is the small stud on the lower side of the starter (when installed) and the factory colors are black/green. The factory wire runs to the integrated climate regulation control module as well as the on-board computer/multi-function clock. When tracing these connections it appears as though they are computer controlled grounds.

Things I've tried:

- Simply leaving the ground small stud off doesn't let the bendix move toward the flywheel and it just spins in the housing.

- Grounding the small stud to the engine block causes the starter to not stop turning over the engine (even when i let off the button). I have even replaced the starter solenoid believing IT to be the issue.

- Just a bit ago, I wired up the ground wire to the integrated climate control module like the factory harness was (factory plug wire black/green). I turned on the main switch, fuel pump switch, and pushed the starter button. The motor turned over one time and stopped. I thought it was a dead battery, so i put a jump start box on it. Same thing. ....Then i seen smoke coming from the wire going to the starter coil right at the solenoid. TOTALLY melted.


So, all this said, I am at a loss as to what to do. I'm hoping you guys can help. Since I'm not using the factory ecu (which seemed to have some crazy switching ground), what are my options here? Anyone here who's swapped an engine with a megasquirt v2 diy have this issue?

Any help is appreciated.

-Ross

[Liquidity]

You don’t even need that wire. No starter needs that wire. I don’t know why you were trying to use it.

[91ironworker91]

I guess I was misinformed. It turns out I had the ignition wire going to the relay unload terminal. I had them backwards. The LOWER terminal is ignition, the UPPER terminal is relay unload. Stupid mistake. Now I know. Thanks for the reply.