2001 GMC Yukon XL

[Fless]

I’m pretty sure he did his best to describe the relay he was referring to for you yesterday. Might take a peak at that post.

What? You’re giving out Free Tips now? What has this forum come to.

Free tips are limited to certain days of the week, due to forum rules. Basically any day that ends in "...day." None of the rest.

 

[AG01YukonXL]

Sorry to hear that. There are tons of guys on here with 800’s. They’ll join in soon.

hopefully so. TY.

 

[Doubeleive]

Thanks to all for the replies. WJBURKEN, apologies, correct I have a 2001 GMC Yukon XL, 175,000 miles. Note: Drivers door switch previously replaced, ordered another, attached; same problem persists… do have an auto page alarm installed (10+ yrs old), aftermarket sound system, horn & rock lights … all functional.

My installer did test the alarm & replaced the brain when he saw the lock issue, had same model on dusty shelf. Going to try and disconnect the battery to see if that would do anything… reset. Also ordered the super relay buddy to test the relays, even though I swapped them out.

Did also read in an old post here from

Matthew Jeschke with same problem on his 01 Tahoe,​

that he removed a “jumper relay” and found that he replaced it the wrong way… waiting for a reply in that post for clarification / location as I don’t see anything labeled jumper relay in diagrams.

on my 00 we ended up having to install double relays to get the door locks to work because there just wasn't enough power going thru.
very well could be the same issue
you should be able to connect a meter and see what voltage is getting to the door locks, gm's cutt-off is 10.4v