My '99 Bourbon K2500 SLT with barn doors recently developed a wee bug... None of the three interior door lock switches (third at the very rear) will lock or unlock the doors. The factory FOB will lock and unlock the doors without fail, so I'm thinking it's not the relay.....? Every other switch seems to work fine, power windows, power mirrors, although I've never been able to adjust the passenger mirror. Does this raise alarms to start checking out the wires going to the passenger door? Could some short be happening in there that blocks out the interior switches but not the FOB? I have browsed through 8 pages of posts regarding door lock issues and the only ones seeming close to my issue involve after-market alarms or remote starters, but my Bourbon is blissfully un-molested. (So far. There will be one hell of a stereo upgrade very soon. It floors me that the factory stereo can make FM sound like AM.) Thanks in advance for any suggestions!