Hey gang-
Been wracking my brain lately trying to figure out the passenger door window on my 94 cummins.
Window goes up, but not down. Last summer the window went up fine, but I would have to fiddle with the switch A LOT to get it to go down. Now it won't go down at all.
There's no clunking / energizing the circuit when you hit the down button from either side.

I have replaced switches at drivers & pass. side controls.
I have checked / replaced the relay in the fuse panel
I have checked door jamb wiring & do not see anything broken or out of place.
I bought another motor (that I verified with test leads), & it goes up & down fine off of 12v, but when I lug it into the truck's plug, I get the same- will go up but not down.
I have verified +12v & -12v at both door switches, at the pins on the back of the switches.
I have verified +12v & -12v at the plug where the window motor plugs in, from the drivers & pass. door switches.
I have put 12v to the old window motor itself, & switched the leads- the window motor goes up & down just fine at the door.
I thought it may be loose pins at the plug in, so I have put slivers of aluminum foil in the connector holes- nothing changed.

Is there something I'm missing??? the motor goes up & down fine on it's own, & I have +12v & -12v at both switches. Everything should work. It's gotta be wiring somewhere

 

OK so last ditch effort I finally figured it out. The only thing I hadn't replaced was the master switch buttons on the driver's side. Didn't think I needed to, seeing how I had correct voltage coming out of it.
At last- she's up & down like normal.
Hope this helps someone in the future.