Rear power window switches don't work.

[240voltz]

The rear windows in my 07 D40 STX still go up and down when using the master switch in the drivers door, but they don't work with the switches in the rear doors. I thought it might be the master switch so I got a new one on ebay, didn't fix the problem.

I had a bit of a search on here but couldn't find my specific problem.

Hope someone can help.

 

[Old.Tony]

The likely culprit is the switch that locks the rear windows. This switch is in the driver's door controls, it only locks the rear window buttons from being used.

It's very unlikely that both left and right rear switches gave up at the same time.

If it's not that switch, it may be the loom in the door that has had that specific wire damaged or loosened.

Last thing to check if all else has failed is the earthing to the rear doors. Test it by attaching a wire connected to a good earth point (battery negative, or one of the bolts under the dash that hold the dash in) and connecting this to the door striker, say.

 

[240voltz]

Thanks Tony.

I tried the switch that locks the windows and it also locks out the front passengers and appears to be working fine. Thats as far as I've got.

It is odd that both back switches are gone, but I wouldn't know if it happened at the same time or not.

 

[Old.Tony]

My "lockout" switch doesn't lock the front passenger window. Now it's sounding like there's a logic error (unless your model was programmed differently). Mine's a Spanish car built in 2009.

Have you tried the earth? Here's something else to try: clean the battery terminals, and run a jumper lead from the battery negative to the casing of the alternator.

 

[240voltz]

Bit of an update.

I took the switch from the front passenger (which I know works) and tried it in the rear doors and no luck. Took the switches from the rear doors and tried them in the front passenger and they worked.

I think I am more confused now.

 

[GunMentalGrey]

Any idea how they are wired? I tried to find a wiring diagram but didn’t look hard.

I presume that 12v is provided to the motor and then the switch earths one side depending on wether you want up or down. Or is it to thebcebtre of the switch. I can’t wrap my head around it because there are two switches, front and rear.

If they work from the front switches and the rear switches actually work it might be something with the earth on the rear doors or wherever the windows are earths.

 

[Old.Tony]

If the switches are working, then there's only a couple of possibilities left.

1) Both rear doors have poor earths. A jumper cable from battery negative to the door latch would give us this answer. If so, we'd need to check the earth route for the doors.

2) Both rear doors have failed window motors. I think the chances are very low.

3) The BCM thinks you're in a two-door not a 4-door and has forgotten about the rear doors. I'm not sure how I'd fix this, I would have thought the BCM can't be altered like that.

4) The BCM connector cable is faulty, or has dirty pins. It's firstly a matter of unplugging it and checking that no pins are bent and nothing is in the connector (how'd it get in there?) but may be worth checking that the harness hasn't been snagged by anything too.