1991 f 150 both power door locks don't work and stuck in unlock position
 

Hello guys.
I have a 91 ford f150 ext.cab. My power door locks have been intermittent for a couple months. Last week they quit working altogether and both are stuck in the unlocked position. Literally, if i manually try to force either knob down to the locked position it just pops back up, and that's with the switches plugged in or out if their harness. I removed both switches used contact cleaner and tested with volt/ohm they seemed to go open and closed properly on the bench. Then reinstalled them. Still didn't work. I found the diagrams that some have posted online and i seem to have 12+ volts everywhere that there is supposed to be. The input/output sides of the harnesses that they are plugged into, with the switches in both locked and unlocked positions. My guess now is the motors, but i wanted to check in here first to see if I've missed something before i have to go inside the door to get at the motor...is there any easy way of getting to the connections at the motors?...and would both fail at the same time? and it appears that everything flows thru the pass. side first then to the drivers motor?....Is there still a chance of a broken wire at the door jam?... I've searched all over the internet and I've seen very similar questions and read the posts responding to them, and that's how I've gotten this far, but the OP never really responds and says what worked for them or what they found out. Any help would be appreciated!
Thanks

Sounds like electrical issue to me..... I would take the door panels off and check the switches themselves and the connectors.... bet you find some corrosion.

The drivers panel is off now and inside looks like you would imagine a 30+ truck looks like. I'll pull passenger side tomorrow and see what's up. maybe i will just throw a couple motors at it, see if that gets it. I'll post again until i fix it in case someone else with the same problem stumbles on this thread...Also i notice before when i locked or unlocked the doors from either switch there was a definite draw in amps as the dome and dash lights would dim for a moment , that's not happening now, i always figured that was normal for our older trucks.