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Electrical power shuts off driving

Every week or so my 2010 Chevy 1500 will lose electrical power intermittently while driving. The engine stays on, seems like it sputters a little bit but I’m not sure. The electrical goes off IE stereo, dash lights, A/C lights, A/C itself, even gauges drop like the car is off, door locks will lock and unlock on their own several times, all of this can happen at the same time or sometimes it’s a random mixture of all those issues, after 5 sec or less the power comes back but shuts off again during the same drive repeatedly. I’m usually able to get where I’m going but when I turn the truck off it won’t immiediately start again even if I try to jump start it, it acts like it’s completely dead. After I’m parked, weird stuff starts to happen, I get a loud screech/buzzing periodically when I open the door(no keys in ignition), or sometimes when I try to start it to, sounds like it’s coming from the dash in the cab, not under the hood, one time the horn started honking on its own repeatedly when I opened the door, I don’t have an alarm. Even with no keys in the ignition, if I sit in the car, I’ll periodically hear “electrical noises” almost like the car is just about to fully crank, like the key is half way turned in the ignition and my gauges will jump a little bit for a few seconds. I usually have to wait a little while before it starts up again, nothing seems to get it started besides waiting an hour or upto over night. I’ve taken it in a couple times but mechanics can’t identify the problem bc it doesn’t happen when I get it to them, The battery is fine the alternator tested good. I’m not a pro but seems like something is drawing too much power and continues to draw power slightly when the car is off

Without seeing the vehicle or running tests on it, the symptoms you are describing sound like a failing ignition switch

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Those are the symptoms of a failed Body Control Module.

https://moduleexperts.com/5-common-symptoms-failing-body-control-module-bcm/

https://www.rockauto.com/en/catalog/chevrolet,2010,silverado+1500,5.3l+v8,1445445,electrical,body+control+module+(bcm),2888

Tester

What about a corroded or scaled over junction terminal? That can cause intermittent loss of power and it’s also easy to check and clean.

I would try wiggling the ignition switch with the keys in it when this happens and see if it changes anything . GM is notorious for crappy ignition switches which causes all kinds of weird stuff .