Dear User of Reddit my E38 doesnt start (again)
I will try to keep it short.
I own a BMW E38 735i from 1997.
The car was in the workshop for 10 weeks. I paid €3000 for EWS module repair and a full electrical power supply (voltage distribution) cleanup/rebuild.
After picking up the car, I drove it for 3 days. It started normally and ran smoothly. The only issue was that I could not consistently rev past 5,000 RPM. Sometimes it would go up to 6,000 RPM or higher, but most of the time it was limited around 5,000 RPM.
So far, everything was fine. I then drove about 300 km to my workplace. After about 150 km, I took a break. When I tried to restart the car after the break, it did not start at first. The starter motor did not react at all. After 5–6 attempts, the car finally started again.
I continued driving to my destination, but since then the car will not start anymore.
I opened the E-box and started diagnosing the issue myself.
It became clear that the green starter relay in the E-box clicks and operates normally when attempting to start. However, the blue relay next to it (DME relay) does not switch.
My measurements so far:
Green relay (starter relay, 5-pin): switches normally during start attempt
Blue relay (DME relay, 4-pin): does not switch during start attempt
When I bridge the blue relay (30 to 87) and turn ignition to position 2, the DME powers on.
When I bridge the green relay (30 to 87), nothing happens, likely because the blue relay is not switching.
Green relay measurements:
Terminal 30: 12V
Terminal 87 (1): 12V
Terminal 87 (2): 0V
Blue relay measurements:
Terminal 30: 12V
Terminal 87 (1): 1.5V
Terminal 87 (2): 0V
That is basically the current situation in my E-box. Can anyone help identify what might be wrong?