Chevrolet Repair: Electric Door Locks wont function, electric door locks, check fuse

Question
99 GMC Yukon SLT, I get not reaction when I push any of the 3 (driver/Psngr/rear) door-lock buttons.  I bought this at auction, no remotes, so I don't know if that works.  I've checked the fuse and replaced the relay, no change.  Lumbar support (on same circuit) works, even when no-key in ignition.  

I've seen this problem from a few on other sites, but no viable fix.  Please help.

Answer
Hi Aaron... did you check for power and ground at each of the switches...check fuse for power on both sides...if you have no power at fuse try jumping power to it...if you have power at fuse but no power at switch check the wires where they come thru the door to cab for breaks...make sure you have good grounds. also try jumping lock motors to see if they work....hope this helps