So I managed to leave my windows down a month or so ago during a heavy rainstorm. Absolutely soaked everything but somehow I lucked out and only lost the up action on the passenger power window. I figured it wasn't the motor because if it runs in one direction it should run both, but just to check I pulled the guts out and tested it. The motor runs in both directions.

That rules out the motor.

Pulled out my multimeter and tested the switches for continuity. Both up and down check out.

Not the switch

I then checked the voltage from the wiring harness in the door. Up action was reading 2V if I remember right.

Is the wiring harness is bad?

I've torn the glovebox out and the kickpanel and discovered that the harness connector sits behind the blower fan system and I assume that I can't get to it without removing the blower fan.

I tried pulling it out by taking out the 3 bolts on the assembly but it won't budge. I tried checking the FSM and can't find a blow apart diagram or anything.

Can anybody confirm What I'm doing right and wrong? Do I need to remove the blower fan to get to the harness connector? Is it the harness or could it be something else?

If I do get the harness connector out I'll add a disconnect that's more accessible and buy a set of doors from my friend that has a junkyard and convert them to manual windows for wheeling.

 

On the right power window switch there are two sets of contacts.

When the switch is in neutral it allows the motor to be controlled from the Master switch on the left door.

Does it work from the Master switch??

There is really no reason to pull all those things apart unless you really want to .

The voltage comes via the door relay to operate the other windows on the door switches.

I am looking at the 94 yours could be a little different

 

I didn't mention it was a 95 4Runner. The window rolls down from master switch and passenger switch.

Even if I don't need to take the harness out I'd still like to get back in there and deep clean a bit.

 

Anybody?

 

A weak and tired motor will sometimes run with no load .

I had one or two worked fine on the bench with a load not enough to push the window up.

Is the window regulator lubed enough water got in perhaps it is rusted

Very seldom will the harness go bad unless it has physical damage

try to get the motor to go up by hooking to it direct with it all in place,

Most wont work unless the door switch is closed which can be a real pain.

 

I've pulled the entire mechanism out and went straight to testing voltage on the wiring harness. The down action contacts only read 2V. The up contacts read a full 12V.

 

Update: during my lunch hour today I went to play with my torn apart window and plugged the motor and switch in just cause i was curious.

IT WORKED!

Somehow both directions began working again so I started bolting everything back together and tested it.

worked with the gear system and track bolted on.

worked with the assembly bolted back into the door

So then I put my window back in the track and tried sending it up and it didn't work.

I then took the window back off the track and it worked again. So I pushed down on it with my hand. Still worked.

Put the window back on the track and it stopped again. So I clamped the window back in the up position and went to clock back in to work.

I get home from work and plug my switch back in to try it and now it's gone back to just down and no up. Same situation I started out with.

I'm completely lost at the moment. Any ideas people?

Just to cover things I've already tested:
NOT switch. continuity in both positions is good.
NOT motor. motor runs forward and reverse when changing polarity through the down action on the switch
NOT the weight of the window. pushed down on it with my hand and it went up when it randomly started working.

I still believe the culprit is the harness as when I connect my voltmeter to the down pins on the harness where it clips to the switch I get 12V but when connecting it to the up pins I get 0V.

 

like WY said, sounds like a weak motor can't overcome the resistance it's facing. does it work when you pull up on the window with your other hand to help it along?
if so, try spraying some lithium/graphite lubricant and make sure everything's aligned right -- maybe loosen, readjust, and tighten the stuff up.

P.S. i replaced one motor with an aftermarket part (forget brand) and it was always *much* slower than the other windows (as in took twice as long to roll up window). I wished i had used an OEM part (e.g. junkyard) instead.

 

Not a weak motor. I went back out today during my lunch break and plugged it all back in and it worked again. Everything is back together now and working great. Still totally stumped as to what caused it.

 

From the water bath maybe things just corroded enough to cause a poor connection .

the plugging and unplugging removed enough for it to now work.

Sometimes the corrosion can`t be seen with the naked eye .

What is really bad is when the meter tells you things are good but when plugged in it does not work.