patrickbenoit

I have a 2001 Chevy Silverado HD1500 6.0L LT. The power locks for all but the driver side front door quit working for both lock and unlock. I checked the dash panel block on the driver side dash and found the 15A unlock fuse fried. I replaced it and the unlock function began working, but lock for the three doors does not. I tested all three relays by feeling/listening for relay clicking and also by rotating them one-by-one to the driver door lock position. All tested positive with expected relay clicks and during the rotation test the driver door operated correctly for all three rotations. I also tested by switching the lock and unlock relays to see if the symptoms reversed. They did not. I've included pictures of the relay type, the block box and the box cover for reference.





I am hoping for other suggestions to test. Last time this happened, I replaced all three relays because I was unfamiliar with testing the relays and that solved the problem. I hate to replace all three when from testing they appear operative. Any suggestions are welcome and appreciated.

Thank you