Yet another rear window problem...

[mel2002]

I have been searching the forums for a fix but have not yet found a problem that seems similar to mine. The window works if you jump it directly at the motor. I have power on both wires to the motor on the volt meter if I ground the meter to the chassis of the truck but not on the 2 wires themselves. I assume if the volt meter is on the 2 wires I would get a + reading with the switch in one direction and a - in the other, but I get no reading either way. My thought was it was a ground issue but we cleaned 2 grounds; one behind the LH taillight and one under the dash. The dash switch was replaced very recently by the PO so I do not suspect that. Is the tailgate switch bad? I have bypassed the tailgate closed switch by putting a jumper from one lead to the other. I know I have to be missing something here because there seems to be know reason for it not to work.

 

[Blue beast]

It was probably wired wrong by the Po or you are mising something maybe a bad connector or corrosion in one of the contacts. Radio shack

has a pen that cleans contacts and leaves a protective coating that supposedly increases the conductivity. Also check your weather stripping

if it is dry rotted and letting water in the gate it could be messing with the motor and contacts etc. Also check your drain holes while you are

in there if it isn't already rusted out it is important to keep them clear so any water that gets in can drain out!! R.S. also carries a pen by the same

company that puts a layer of gold onto the contacts to keep them protected.

 

[desert4wheeling]

You have the exact same problem I do. I just replaced my dash switch, jumpered out the tailgate safety switch, still doesn't work. I haven't found any obvious connection problems. On the good side, I've cleaned and lubricated all the tailgate inner parts, installed a new motor, replaced the inner glass runs, and replaced the weather stripping. When I do finally figure out the problem my rear window should work great!!!!!!!!!!!!!

On an old post I read that someone suggested disconnecting the circuit at the connector behind the drivers side tail lamp. There will be 3 wires at that connection point: 2 blue (PWR) and one black (GND.)There you artificially insert power to see if the tailgate switch works/if you have a problem before or after that point. I'm gonna try that next.

 

[Seabronc]

Here is the circuit. Older trucks had a connector behind the LH tail light, newer ones do not have that connector. The most common failing connector is the one on the LH rear cross member, often the wires corrode until they don't make a connection any more. I ave seen them actually break off the connector. Another common problem is the safety switch in the LH tail gate latch, people often jumper that one out. That switches function is to prevent you from raising the window with the tail gate open, but I for one am smart enough not try to close the tail gate with the window up or partially up. It is very useful to be able to move the window with the tail gate down for maintenance purposes.

If you look at the diagram you will see a black with white stripe wire. If you put a meter on it you should have +12V all the time and the ground returns through the driver switch. If using the driver switch one of the other two wires will have +12V and thee other will go to ground and reverse function depending on which way the driver switch is pressed.

Note: the tailgate switch will not work if the driver switch is stuck in UP or Down position, the switch sticking is a common problem with the older style switch in the 80 - 86 Broncos.

Good luck,

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[mel2002]

I found a work around! I found out it was caused by a faulty rear (keyed) switch. I fixed it by bypassing the rear switch. I opened up the tail gate from the inside and disconnected the wiring harness closest to the window motor. I used some long jumper wires to run the motor directly off the battery to get it down and open the gate. Once inside I ran 2 wires connected to the motor wiring with male spade connectors to the large 3 wire plug behind the LH brake light assy. One wire is hot (feeds the rear keyed switch) and the other 2 are from the dash switch which reverse polarity to the motor for up and down. Plug the 2 wires from the motor into the 2 from the dash switch with male spade connectors. Try the dash switch and see if you guessed right and reverse them if the direction doesn't match the direction of the switch. You can only open it by the interior dash switch, but hey that's better than nothing!! It may not be a permanent fix but but it should last until I'm done with the truck

 

[Seabronc]

Glad to hear you got it working.

Good luck,

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