No Crank when Headlights off

RobC76

Well-Known Member
Pulled front half of harness out of car and putting on table to work on it. It was a ground coming from the BCM that was tied to a ground coming from ECM instead of being grounded. This fixed all of the back feed / headlight issues but now it won’t crank lol. I will dig into the no crank tomorrow. When going to crank position on key the BCM crank relay engages but I did not have schematics / pinouts of the ECM / Fuse center stuff which I’ll get tomorrow. Really appreciate all of everyone’s help. Wiring can be quite challenging.
Thanks again
 

Gtstorey

Goblin Guru
Pulled front half of harness out of car and putting on table to work on it. It was a ground coming from the BCM that was tied to a ground coming from ECM instead of being grounded. This fixed all of the back feed / headlight issues but now it won’t crank lol. I will dig into the no crank tomorrow. When going to crank position on key the BCM crank relay engages but I did not have schematics / pinouts of the ECM / Fuse center stuff which I’ll get tomorrow. Really appreciate all of everyone’s help. Wiring can be quite challenging.
Thanks again
And some think a EV donor would be a good idea.
 

RobC76

Well-Known Member
Solved…
So the two needed grounds that were tied together instead of going to ground solved all of the issues. As I posted last night I had no crank function anymore. Chased and pinned out every plug in the harness. That only took 4 hours lol. Found that the clutch switch was bad. Ironically failing in the middle of it all. Swapped out brake switch and manually actuated it. Cranked as normal. If I would have been through this first making the harness would have been a bit easier!
Thanks for all the ideas and help!
 
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