07 equinox 3.4 electrical problem. after replacing head gaskets during test drive, car display said stabillatrack problem, then car stalls, try to restart, car starts and runs for a few seconds and stalls again. after a few trys to start nothing. no starter no dash info no driving lights no head lights. Do have park lights at rear but not in front. I am a former diesel tech am familiar with electrical problems,this problem seems to me to be ground . problem is i can not locate the grounds that serve power distribution panel. Thanks Joe

 

Sounds like a textbook case of a bad battery and/or alternator to me.

 

new alternator and battery voltage at 12.5

 

I'm not sure what you mean by this. A positive cable would go to the fuse panel, not a ground. There are only two main ground connections coming from the negative battery cable/terminal. One goes to the chassis near the front left strut tower. The other one is attached to a stud between the engine & transmission. Everything else just connects to the chassis for ground throughout the rest of the vehicle as necessary.


That battery voltage sounds good, but it really doesn't mean much. The only accurate test for a battery is a load test.

 

I am sorry i did not explain my self better. Did a load test on battery and it holds at 12.5 volts. Also when i did the head gaskets the alternator had noisy bearings so it was replaced with a new one.I did locate the grounds at the engine block and strut tower. I removed cables and cleaned the connections,also at battery negative post there is a ground that had broke, it was repaired. What i have found in checking for power at the fuse panel.relay #31 not clicking when ignition is turned on,and fuse #16 thru #29 have no power with ignition in run position I checked for a ground at relay 31 with ignition on, no ground to activate relay. I do have standing power and switched at relay 31.Ignition switch bad maybe? I also did try another pcm, no change. A local repair shop has a 07 equinox for spare parts, took all the relays and changed them. Also, I am very thankful for the reply's and trying to help me find the gremlin in this car.

 

Body control module (BCM) maybe. Mine failed upon installing a new battery just off the charger. A Float voltage on the battery will kill the BCM.

 

I had some time to look into this a bit deeper. The circuits you said have no power are linked to ground G111 in the diagrams I looked at. This ground is located under the right cylinder head (closest to the firewall) according to the picture I've attached.




2007-2009 LNJ engine harness grounds

 

Sorry I did not answer you sooner,been busy trying to get hay in barn. That ground is in a location that might have been broke by exhaust manifold when removing head,will check and let you know thanks again for your help.

 

well I finally had chance to check the ground at back of engine,cleaned it and replaced. well i have power on all fuses that were dead,but anti theft locked me out wont start. Done some checking and found procedure for resetting. I got the car to start, runs ok but now I dont have any heaadlights driving lights or park lights. Again thanks for all your help. Any thoughts on new problem?

 

After some more checking I have found that none of the lights at front of car work. no park no turn no hazard no headlight. ????????