I have a 2009 Yukon that experiences a complete electrical shutdown (like if I turned car off and removed key). The shutdown happens sporadically with no particular cause. It has rained everyday here in Fort Lauderdale for 45 days straight. About two weeks ago my Yukon’s battery went dead after running the radio for two hours without the car on. I received a jump and the everything seemed fine, but the passenger’s A/C came out hot for some reason. Once the car was turned off and on again all went back to normal.
This week the Yukon began shutting down. If I am driving it seems to just flicker of and on, but keeps on moving. If I turn the car off I have to wait 5-15 minuets then it just starts normally.
I had an after market sub-woofer w/amplifier installed (Best Buy) about two months ago. Don’t know if this matters but it has been the only electrical modification done on the car.