I have had this issue going on 2 years now and it is annoying the hell out of me, please help if you can. I have a 94' 3.4L ( I know the engine sucks) that I absolutely adore; but whenever I turn on the exterior lights (just regular low beam) my door ajar beep constantly sounds. Not sure if its a wiring problem or it can be controlled by a fuse removal. Can anyone point me in the right direction? I would like to go back to driving her at night time.

 

Your best bet would be buying a Haynes manual from the local auto parts store.
Reads like BCM is getting an erroneous input signal or maybe a cold/cracked solder joint internally.