Gauges and Transmission going crazy

jminter6001

New member
Jan 27, 2024
2
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28112
For about a year now I've been battling with what I'm guessing is an electrical issue. I'm driving a 2015 Chevy LML. (Tuned, CP3 conversion, Airdog system). All my gauges will start going crazy along with the cluster lighting up like a Christmas tree. I'll get ABS warnings, trailer brake warnings, and stabilatrak warnings. Then my transmission will start downshifting and upshifting, and when changing gears it changes really hard, shaking the truck. It happens randomly. I did figure out though that whenever I turn my AC on, this weirdness happens immediately. Any ideas? I've spoken with multiple mechanics, and they said without a Check Engine Light they don't know where to start looking. One mechanic rode with me and saw what it was doing and tried to read the codes. It threw TONS of codes, and he didn't know where to start. It was throwing lots of BCM and ECM codes. I feel like cutting my losses and just dropping the truck off at the scrap yard. I can't afford to spend tons of money hunting for a problem we may never find.

I'm thinking to start with taking out all of the AC components and put new ones in. What do yall think? I'd hate to take it any further.
 

aketay

New member
Jan 27, 2024
6
3
3
Peculiar, MO
Start with the easy stuff first, if it only happens when you cycle the compressor, check for groundout on the wires that activate the clutch. It should go back to a relay in or near the fuse box. If you have continuity on both wires, you have a bare wire to fix. If that checks out good, pull your main fuse panel under the hood and inspect the bottom where the harness feeds the fuses. IIRC, they had problems with water getting in there and shorting out the pins. Good luck!