Ok ... I've gutted the M, and removed almost all the wiring. Obviously, I got a bit happy with the clippers, and now it won't start :help

1. Does anyone have a wiring diagram for what's needed to actually run the engine in a 95 M3 race car? Forget lights, wipers and all that crap (for now). I just want to start it! I have a bently, but I can't really determine what is needed to actually run the car. A picture speaks volumes!

2. I have been tracing through the wiring, doing diagnostics. I believe the main relay works, and I'm getting power to the starter (it cranks) and power to the fule pump relay. Following the bently tests for the fuel pump, it say to test for an ECU switched ground at terminal 85 when in start and run .... just so I'm clear here, what's the proper way to test for ground? Also, it seems that in start and run, I get +12V at the brn/grn wire (terminal 85) to the fuel pump relay, and NOT ground as indicated in the bently. Essentially, I'm getting -12V going to the fuel pump, and so of course it does not run (the pump works fine with direct +12v) ... I'm kinda stuck with what to test next?

Some notes:
- the engine wiring harness was not touched (from the round connector on)
- only things left are Main relay, Fuel Pump relay, O2 sensor heater relay, 2 ABS relays, and light relay (for brakes), plus associated fuses (all good!)
- ECU is getting +12v from the connector at the various points, and it's also getting ground.
- Just to confirm, the guage cluster is not needed to start the car, correct?

Thanks for any assistance on this guys.

ews? what build date?

ews? what build date?

Sorry ... 03/94, no EWS (if that's the starter immobilizer?)

I have a copy of the wiring diagramme. EMail me - it IS big!

Dan Law

Cluster not needed. Verify operation of all relays - pop open the tops and watch them. Does it turn over? Is there fuel - pump is running when in start position and injectors are pulsing. Also check for spark - is there an AC voltage at the coil connectors?