2002 gmc yukon electrical problem

hello i have a 2002 yukon that drains the battery every 2 days when i let it sit. it is the 3rd battery a had in it this month. nothing in the truck is left on or obvious any ideas. thanks, rich

Do you leave your Keys in the Ignition all the time? I have seen batteries die over night because the computer is powered up when the keys are left in the ignition.

I had the same problem in my 01'. I am not exactly sure what relay it was but I had a relay constantly opening and closing rapidly after I would close my drivers door. Every once in awhile I can hear it spaz-out and I just bump the dash under the steering wheel and it stops. You may want to start there. I haven't had time to investigate my problem totally but the battery drain has stopped.

I am having problems with power surges on my 02 gmc yukon xl. It started over a year ago. During that time a one year old battery ran down and was replaced under warranty. A check of alternator doesn't show that it's bad however the power surge shows thru lights (interior and exterior) strobing. Took to dealer and was told GMC recommends a alternative wiring harness. I'm thinking about installing a new alternator. Please Help!

My wifes 97 blazer had door locks cycling killing batt. Traced to rear hatch key lock switch,unpluged no more dead batt door locks will still work just cant lock or unlock rear hatch with key.

check for a recall on the dash board. they short out. don't know about o2 but 03 has it