As the title suggest, I'm having some odd behavior out of the power door locks in my 96 CCSB 7.3. So to start, there is a factory remote keyless entry system. The lock and unlock seems to work on the driver side door ONLY with the key fob or when you do the programming function by shorting the pins in the plug. The switch on both the driver and the passenger side do not do a damn thing except click when operating unlock only. Lock does not have a click at all. Again, only when using the key fob, the driver door will lock and unlock and the passenger side will lock but will not unlock. I figured the passenger actuator was going bad but after replacing it I discover another oddity. It does not matter if you press lock or unlock, the actuator will only lock. So it locks, and then when pressing unlock, it just keeps trying to push up like its locking. So no polarity switch? The rear doors do not have any operation period. I have checked the door jamb wires on all doors and they seem to be okay, the rears have all been repaired already. I've wiggled them while actuating the switch and no dice either. Any suggestions? I have no idea where to go from here.

 

Check the wiring to the doors, mine is starting to fray and a short can do what you are experiencing

 

Power to all doors runs threw the drivers side lock switch first. Check to see if the drivers side lock switch is jacked up. A bad switch can cause weird problems.

 

May want to pull that OE keyless box and check for cracked solder joints or just bypass it and go with an aftermarket setup to save your sanity.

Cracked solder points cause piles of random issues, moreso when cold weather. My aftermarket kit is from Bulldog, ran about $30.

Also the front switches cause issues, mine did so I douched them out with Deoxit. Helped quite a bit!

 

I forgot to mention I have replaced the switches. I checked the wires in the jamb and they seem okay too.

 

New to your or new new? Either way, I would verify they work correctly...never know with new junk

Can you pop rear locks with 12V?

 

Cab grounds under the cab can make for weak power to door locks.
There are also one in each kick panel in front.

Try cleaning them first to rule it out.

 

They were new, albeit from Amazon. I pulled the KE module out yesterday and opened it up. I could not see any cracks on any of the solder joints. I'll get around to taking the rear door panels back off and testing the rear actuators but when I was changing the window motors I could tell they were original and probably failed long ago.