Strange Power Window Problem

[Brynjminjones]

I've just discovered a newly developed quirk in my 1991.

The driver's side rear window doesn't work from the driver's door, but does work from its own switch.

However, it gets a touch more weird than that (of course)!

When I operate that window from the driver's door, the voltage gauge drops like there's a huge load, so I know the switch is still trying to do something.

I then thought to try both switches at the same time. When I operate the window from its own switch it moved nice and quickly, but if I use the switch on the driver's door at the same time it slows right down.

How can the driver's door switch not be working, yet still causing a huge load on the system?

[MysticRob]

Sounds like it's the driver side switch then, all other things, like the rear door wiring, being equal.
I would remove the driver door panel and swap around the connectors for those windows and see if it's the switch or not.

[Brynjminjones]

Yeah, looks like I'll have to dig into it. It must be the switch I guess as it will go up but not down.

I've had that b*stard door panel off about 5 times already this past week or so!

[Heavy_Metal_Thunder_81]

High resistance in the drivers door switch. The contacts are probably corroded over. You can open them up and clean them.

[Brynjminjones]

Unfortunately it looks like it's a little more weird than I thought!

I've had the switches out and they tested fine. I hooked the rear switches up to the front windows and they worked perfectly.

I also tried a known good switch on this window, and it still didn't work.


When tested with a multimeter, I found that the two wires leading from this switch both had good continuity to ground.
I'm guessing that there shouldn't be continuity when the window isn't operating?

[Brynjminjones]

Right, I've been investigating a little further and have gotten stuck.

I'm trying to follow the wires from the driver's door switch panel to the rear left power window.

The wires in the driver's door are the correct color and I can follow them through the door jamb.
However, I can't find them under the instrument panel.

I'm following this page from Oljeep.

The connector I can't find is the one circled:

Power Windows by Brynjaminjones, on Flickr


Any idea where to look?

[wiley-moeracing]

Testing for power, ground and continuity only is half of what to check, you need to see what the voltage drop is and amperage draw to see if your wires are corroded or broken inside to get a complete answer. You can have just 1 strand of the wire ok and it will show power and ground but will not allow the proper amperage for the circuit when in use.

[Brynjminjones]

Yes you're right - the reason I was trying to trace the wire was to find out where the short was as it seems like something was shorting to ground.

Anyway, I've found the problem now - one of the wires on the rear door switch was shorting against the switch casing!
Looks like some idiot (no idea who that could be!) may have damaged it whilst working in that door last week!

I've also figured out why I couldn't trace the wires properly from the Oljeep diagrams - it looks like some of the diagrams are back to front!
All the information for the rear right door was actually for the rear left, and vice versa!

I was using the 1990 diagrams, and admittedly mine is a 1991, but that's the first thing I've found that isn't right.
Hopefully that might be some useful info for somebody else in future!

[DarkMonohue]

I've also figured out why I couldn't trace the wires properly from the Oljeep diagrams - it looks like some of the diagrams are back to front!
All the information for the rear right door was actually for the rear left, and vice versa!

That may have something to do with the fact that your vehicle was built as RHD and the diagram probably assumes LHD.

[Brynjminjones]

That may have something to do with the fact that your vehicle was built as RHD and the diagram probably assumes LHD.

That would be a very good point, but I should point out that my GW is actually completely US spec and is LHD. We never got the later ones over here, so they're all imports

[DarkMonohue]

Ha! So much for that theory. I must have had yours confused with someone else's older FSJ.