HELP! 2000 Celica GT refuses to stay locked

[I AM SARS]

Hey guys, so just tonight my 2000 Celica decides that it doesn't want to lock anymore when the key is out of the ignition. When the car is running, the car doors lock just fine. When the car is off and I'm holding the key and try to either use the switch to lock the doors or manually move the lock on either door, the doors lock for a split-second, then unlock. What's the deal? I've checked Fuse #27 (manual said that one controls power locks), checked out ok. I already searched the forums and nothing I could find helped.

Any advice would be appreciated. I hate the fact that my car is now constantly unlocked when I'm not around it. Thanks!

(edit): So I just thought of trying to lock the doors with the key outside the car...go figure it worked...so looks like it's just an issue with the switch and manually locking them. Still would like to figure out why it won't lock any other way though.

[Bitter]

try newcelica.org, that forum has a lot more info on the system than here.

[yotamech]

i would pull that fuse and try locking them manually you may havea wiring ghost most likely an accidental ground if it stays lock. look for the easy signs like a bare wire and start probing with a test light. (with the fuse back in.)