This just started: ALL (seven) switches ONLY work when front passenger door is OPEN. The wiring bundle between passenger door and body is wrapped tight, looks good, protected by rubber accordion boot. Where do you think the short is? Do you suggest I take passenger door panel off and inspect for a short/crimp? '99 Blazer I shoved the wiring bundle in/out/up/down (with the boot off and the door open) and could not reproduce the short. The short happens just a millisecond before the door latches...While rolling the drivers window while closing the pass door, the moment it happens there is a buzzing/knocking from the driver's window motor, then it dies. Opening the pass door while holding any switch instantly brings the motor(s) back to life.

 

Yeah, pull off the door panel and investigate. If you're sure you've narrowed the problem down to the motion of that door, I bet the problem is in there somewhere

 

Best guess or opinions, please! I took the door panel off, inspected all wiring harness/connectors. I found that when the LATCH is open, all 7 switches work, when the latch mechanism clicks in to the 1st stage lock, all switches fail. This is regardless of the position of the door. The latch is not binding (when I lift the door handle, it springs open whether it's in the 1st stage or [would be] fully closed 2nd stage latch. I lubed it, actuated it with my finger or a screwdriver neck...no change! I pulled and tugged on every wire, harness, connector, and can not simulate a short. And the latch is quiet, smooth. I even changed the door's hinge pins and bushings just because I had them here. Door closes smooth and straight. Also, the power lock switches both work all the time. What in a steel locking mechanism would be causing a short or open???

 

Unfortunately I think you might have to track the wires back to where they go under the dash. Sounds like one of the latch wires is ground out the window wires in the bundle.

But that's just what I would do, I'm no electrician lol.

Very interesting either way, good luck

 

DonL and Cleburn: I soaked the pass door latch AND actuator with PBlaster, then electronics parts cleaner, now all power windows functions are better-than-ever, with no power drain/short. Whatever was shorting (or causing lack of ground, possibly) got washed-out. I know doing that's not recommended, but I wasn't afraid of destroying the actuator since I'm ready to replace it if it acts-up. (Original factory parts with 217K miles and 20 years service.)

 

Glad to hear it's fixed either way!