I'm having trouble with my automatic door locks. 2000 2dr 4x4 Blazer. The door switch works correctly which tells me my problem is with the remote system. Sometimes it will work, but it's increasingly getting worse (both lock and unlock). I have two original FOBs and one new one (all have new batteries). All get the same results. So I'm thinking...is it a relay going bad or is the receiving unit going bad. How can I check either one or both? And where might I find them??

 

Try removing the cover of your FOB, and clean the black contacts of the buttons on your remote with alcohol. Both the rubber and circuit board. I used a Q-tip to clean mine and now I can use it on the other side of the parking lot as opposed to 2 feet away.

 

I was skeptical of this because, as I stated one of my FOB's is new. I did it anyway. When I opened it (the new one) up it looked really clean. I went ahead and cleaned it!!! It works just great now!!!!!!

 

It might have been new....8 years ago.

That's great that we got them working!