The windows on our TJII all stopped working this evening. I've checked fuses, swapped relays and no change.

I back probed the wiring going into the drivers door switch and there's 12V, which I think rules out relays & fuses anyway.

Does this just mean the drivers door switch unit is kaput?

Somewhat embarassingly I can't unplug the wiring loom plug from the switch unit - I've pressed in the little tab and pulled at it until my finger hurts - is there a trick???

It may or not be a coincidence that the all stopped a couple of weeks ago but then the relay needed replacing.

According to the circuit diagram, I'd say the most likely culprit is a dodgy earth. From what I can tell, so long as the relay and all fuses are ok, even if the driver's door unit is cactus the individual door switches (on the 3 passenger doors) should still work as they get power from the relay via a separate feed (your post doesn't mention if you tried the passenger door switches or only the driver's door switches...if the pass door switches work then most likely the driver's door unit is dodgy as you suspect). The only commonality I can see between all windows, other than the relay, fuse and fusible link, is the earth circuit which is shared by all windows. It should be a black cable running to the driver's door unit, no idea where it's actually earthed but might be worth checking this wire's continuity to body earth. Can't help with the plug, some have a tab that needs to lift rather than push in, dunno with that one. It might just be tight as a... well, it could just be tight and needs a bit of a wriggle to get apart.

None of the switches on the other doors work :-(

Backprobing the drivers switch with my multimeter showed 12V between the blue and black wires. Could the window child lock switch knock out the individual door switches if it is permanently stuck? The lock switch moves in and out but maybe it's broken inside?

Thanks for writing back.

Also from the manual.

Power windows and sunroof do not operate

BEM supplies power to relay to operate windows and sunroof.

Probable cause
Malfunction of window relay.
Malfunction of the BEM ECU.

Turn ignition ON. Test voltage at BEM pin No.
28. Voltage should be zero. Turn ignition OFF.
Voltage should be zero then go to 12V after 30
seconds.

If not, Check supply fuse. Check wiring between the
window relay and BEM pin No. 28.

There should be a link for the manual somewhere, got that from sect 54C, and 54, troubleshooting. Gets a bit complicated from here.

I'll have to dig out my pdf Mitsubishi manual (I've been looking at my paper Gregorys one). You've made me remember the door remote stopped working on Friday - I thought it was a flat remote battery. So it's the BEM / power I need to replace...

Check the fuse in the little yellow box in the under-bonnet fusebox, if I recall correctly this is the fuse for the BEM. Having said that, if the problem is with the BEM the power window relay shouldn't operate and there shouldn't be 12V at your drivers door unit. I think.

They look OK. Also saw fuse inside with door lock icons, it is fine too. So it looks I need to replace BEM, ECU, ignition barrel and door and tailgate locks? Am searching the forum for info on that now. Can see a TL set from Mitsfix on ebay for $295.

That's a bit drastic at this stage, I'm not convinced it's the BEM if you have 12V at the driver's door unit. I'd be doing a bit more checking on that unit and possibly grabbing one from a wreckers and doing a swap (if you can get that plug apart), could be a short or could be related to the child lock button.

Hmm. Door remote not working complicates it a bit. Will see if I can swap over to another window switch i first instance.

You can pretty easily take apart the switch and have a look. Do some tests on it and even bridge the child lock and see what happens... If you do, be aware of the little spring on the side of the child lock switch. Its fairly easy to lose. Im not particularly familiar with the electronics... but I believe the child lock is an earth switch and the windows regs get a constant + from the bem.

The way the power window circuit operates is the Main switch is powered by the blue wire and distributes power through to all the other windows. They are not separately powered.
The BEM connection to the power window circuit comes into play as only a timer when the engine is turned off. The blue wire, has power for an additional 30 seconds supplied by the BEM.
If you have power at the switch, then the relays are working correctly as is the BEM.

The wires may have a circuit between them in the plug, but the switch pins may be filthy, corroded or have had liquid in them at some point. See if the earth pin is heavily corroded or blackened. Then clean it and it should sort your issue.

Or pick up any power window switch from a wrecker - TE through to TJ2 are the same switch. Even if its woodgrain. You can swap the black surround. The switch shouldn't cost you any more than about $20

Mike.

And so this morning the car wouldn't start for my wife. Battery was 11V on multimeter and is now on charger. Hoping it will take the charge and start tonight. Curiouser and curiouser. Feels like we're watching a slow death :-(

Two lots of good news - the car started tonight after charging and I've managed to prise the loom plug out of the window switch unit. The maon power and earth wire pins are black, but there's no sign of water damage. I'll clean up the pins and see if that brings it back to life. Inoticed tonight that the light in the window switch doesn't come on.

Would this soot be part of the reason it's not working?

http://postimg.org/image/ukyw2s92t/
http://postimg.org/image/ukyw2s92t/

signs of life... seemed to be dead on testing but wiggling loom plug in the socket got the auto up to engage and the window is now closed. Lots of pin cleaning to do tonight.

It works! The light isn't working (is it easy to get at by removing the tiny circlip and rod from the middle of the rocker switch??) but all four windows now go up and down. Thanks Mike for the pin cleaning tip!

Good result! The soot possibly indicates a fair bit of arcing over a goodly period of time, cleaning up the contact points with a bit of emery paper and some electrical contact cleaner would be the go. I've not disassembled one of these before so not sure re the globe. The plug pins being black is a bit of a concern, particularly with your battery issues, as it suggests a possible short somewhere, though I'd have thought a fuse would have blown in this case. Once it's cleaned up it'd be worth doing a few checks with your multimeter to make sure there's minimal current flow between the + and earth pins with no switches down, otherwise there could be a short in the globe or the one-touch-down circuit somewhere.

Would this soot be part of the reason it's not working?

http://postimg.org/image/ukyw2s92t/
http://postimg.org/image/ukyw2s92t/

Looks in worse condition than the one on my TL I opened up for a similar reason.
A good clean and a look for burnt tracks needed, the switches themselves tend to burn on the contact faces but they are fairly robust and can be cleaned up, scraping the rocker switch contacts with a sharp knife worked for me.
The blackening looks unusual, did something get spilt onto the switch block? (sugary drink perhaps?)
Needs a good clean, hopefully there are no fried tracks. (They look ok on the photo)

Edit: beaten to it . . .

Sounds like youre getting somewhere finally. Congrats! Do you know why the battery was so low?
I changed my drivers window switch light a year back to go with my red led theme throughout the car. As youve just read, it is an led (a 3mm one)... So Id be weary as to whether the globe was what was at fault. Though either way, its not so easy to get to. The led is in a tunnel and is soldered onto a circuit board. I recall having to drill two plastic welds to get to it to, but cant for the life of me remember why. Then I desoldered and popped it through the tunnel. People think the C is for Circlip, but its actually a case of it popping off and disappearing and then you exclaim jesus Christ! I have a piece of wire holding the rod in as I couldnt find the C-clip box.
You can put your multimeter to the back of the led and see if it is getting power before you consider removing it. If you decide on changing the led, I can set you up with a red led.

People think the C is for Circlip, but its actually a case of it popping off and disappearing and then you exclaim jesus Christ!

:D I was worried it was gonna stand for something else entirely for a bit there...!

:D I was worried it was gonna stand for something else entirely for a bit there...!

Well there is definitely more than one thing is can stand for, but this is a family friendly site! :)