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2011 Silverado AC/pass window issue mechanic can’t seem to find
I’m not sure if I’m doing this whole forum thing right but I’m need of desperate help regarding my 2011 Chevy Silverado.
The AC has been turning on and off randomly . We also noticed when this occurs the passenger window can’t be rolled down and makes a weird sound when we try. I’ve noticed it especially happens when we put the AC on high... reminds of when something short circuits.
Its got a brand new evaporator which we recently had done I want to say about two months ago at Autonation Chevy service center. It’s a $2000 job! They said everything else was fine at the time also.
Took it in last week and waited 3 hours only for them to tell me that the AC was working just fine and they couldn’t find any problems! They even drove the truck for 15 mins and it didn’t act up on them!
Anyone have any idea what could be causing the AC to randomly shut on/off and for the passenger window to not work as well?? The AC dashboard lights also go dim when this happens! I want to figure this out and point it out to these damn mechanics!
Thanks so m
All roads point to G200, or a ground splice to it, or ground junction block. Get to the black wire of the Passenger window switch and I reckon you'll find voltage there that has no business being there when this happens.
Basically I'd rig up a test light connected to known good ground. Backprobe the black wire, and connect your test light to it. It should light up if it's losing the ground. Might have to operate the windows for it to light up maybe.
Did this start after the evaporator was installed? I don't know where that even goes. But look at the last picture in the imgur album which shows the HVAC unit. Ask whomever installed that evaporator if they touched or removed anything near that g200 ground or junction block.
Of course it would help your mechanic if you can make this fault reproducible. In the ground distribution diagram (the one where i wrote "check this" in red) everything in that picture uses that junction block and ground point. If you can turn on everything that attaches to that ground I think you can make the issue happen reliably.
I like jreardon's ground theory. Another way to easily test it would be to reproduce the symptom, then attempt to use the DIC switch or one of the instrument panel power outlets. They use the same ground circuits as the HVAC module and the passenger window. If the switch or power outlets also stop working, then you're on the right track.
