Okay, so I just recently bought this 1990 Ford F150 with the 302 and 3speed W/Overdrive. It's the Lariet trim package and has power doors and windows. The power locks don't work from either control panel. What could cause that? A bad motor?

 

It sounds liek the switch on the drivers side door is bad or un hooked. The passengers side gets its power through the drivers side switch. Thats where I would start looking.

 

Alright, I'll have to check that tonight when I get home. Thanks. I'll have to get new door lock cylinders too because the previous owner lost the door keys after the power locks stopped working... Is it possible that both the power locks and the driver side window switch were disconnected? Because neither work, yet the passenger side window switch works on both sides of the truck...

 

Check fuses also

 

I've checked them all under the dash, they all seem fine.