Gary KJ6Q - The seat belt lock selonoids lock up when defeated because 12V power applied "unlocks" them. If the electrical system is damaged in a wreck (bye bye battery), D/C wants to make sure the belts will lock up and save your life. Locked is the default mode under "no 12V anywhere" situations. Unplugging them places them in this mode.
How do I know this for sure one may ask? Illflem, how correct you are. There is a very specific test procedure for the latch mechanisms in the Chrysler service manual for Ram trucks... . which the UPS man conveniently dropped off today. I must say I doubt anyone would have the will power to type all that is involved with this safety system in a single post. Chrysler knows (I can tell) that the seatbelt system is EXTREMELY important to fix properly and does a wonderful job of clearly telling whats involved, how it works, and how to troubleshoot and correct.
The system is somewhat complicated since they could not place the normal pendulum mechanism in seat-frame mounted seatbelt systems (quad cab front seats)... cause the seat can be leaned back and cause it not to work. So in come the electronics stuff. The manual tells how to test the system in a "test mode" you put the truck in. Key on-off-on-off 3 times then push in the cigar lighter within 5 seconds believe it or not. Then the selenoids lock and unlock by opening and closing the door. Cool Huh?
Anyway, I cant go into all the fine details but with the manual, finding out the problem should be easy. The Seatbelt Timer Contol Module (STCM), which takes input from the ignition switch, door switches, and airbag control module is suspect after my reading, but the wiring voltage tests could prove otherwise.
The manual will prove its weight in gold soon. I would encourage everyone to try and get hold of one if you dont already have one. Funny thing was, the manual specifically states if this system is not working properly, the batteries will go dead

I found out the hard way... although most who read this will never have this problem ever.
PS: FWIW the pendulum has been replaced by and electronic G-Force mechanism. From what I've read I could park my truck on a 45 degree slope to stop all this silly battery drain stuff
