Started my ‘06 SS up yesterday and my window barely rolled up. Went to take off and my a/c died down real low then came back. After driving ab a mile or so I turned the a/c back on and it was fine. Windows went down fine. Had the car scanned and it showed brake switch code and a Tcm code. Battery and alternator tested great. Just had a rebuild done around 3,000 miles ago on transmission. Went to trans shop and he hooked up (this was a couple hours later) and it never showed a Tcm code. It’s been a good car over the past 3yrs. Purchased it from original owner which was an older gentleman that kept it in a garage with a cover on it. Had 114,000 at that point. Other than a water pump and the trans I haven’t had any issues. Just routine maintenance. Anybody have any suggestions. Car has 152,000 on it.

 

Check all your grounds. When I say "check" I don't mean just look at them, I mean unscrew the end of each ground strap or wire, then, using steel wool, clean the end AND the area where it's mounted, then reassemble. Clean metal conducts current, oxidation doesn't. Even the slightest amount of oxidation will adversely affect current flow. Changes in temperature will cause things to expand/contract. In a compromised connection such as one affected by oxidation, a slight expansion/contraction can cause the connection to open/close.

 

Okay thank you. I will start chasing those grounds down after. Hopefully it’s that easy of a fix. Reading through these forums scares the hell out of me😂