The turn signals, mirror lights, interior lights are randomly coming on in my 2001 tahoe when there is no key in the ignition. I replaced an alternator recently...At that time the technician suggested I may need a new battery...i have never known a dying battery to cause the lights to come on and blink inadvertantly...anyone have any experience?

i am a brand new user of this forum so apologies if I have posted this in the wrong place

 

Welcome to the forum. Turn signals or hazards? What was the reason for the new alternator?

 

150,000 miles was the reason I guess. The lights that are blinking are the headlights not so much the hazards

 

Welcome to the forum.

If this started right after the alternator replacement, then I'd suspect some wiring in the vicinity of the work being done.

 

You do realize there isn't "not so much" this or that when trying to figure out the possible fault path. Try removing the DRL relay from the underhood fuse block and see if the headlamps still act up. If they don't but the other symptoms persist, the BCM may well be the culprit.