Bronco Forum - Full Size Ford Bronco Forum banner

1 - 4 of 4 Posts

·
Registered
Joined
·
48 Posts
Discussion Starter · #1 ·
The rear window on my '78 is stuck in the down position. I have tested all the way to the tailgate and have power & good ground. I installed a new motor about 3 mos. ago and it has worked fine until now. I rolled it down to get my tools, and when I went to roll it back up - NOTHING! :banghead Does anybody know if you can get the window up manually? I don't want to take the window off the track if I don't have to... Besides, the torsion bar makes access a real pain in the ass! Thanks for any help!!!
 

·
Driving Stuff Henry Built
-90 xlt, 351w, e4od, man 1356, 3.55, sag, warn hubs, 35s. -73, 400, np435, d20j twin, 35s
Joined
·
8,519 Posts
Have you tried pushing the driver's side of the tailgate in while you turn the key? There's a switch in the left latch that can act up, that is a pretty common problem. For mine, I ran jumper wires direct from the battery to the motor to run it to get it open & apart, you might be able to get it closed the same way.

Here's some general window info that might be helpful, especially the links:
The stuff below is cut & paste from an earlier reply, but it covers a lot of tailgate window stuff. Use what applies to your situation.

Does it make any noise at all? Like the motor's turning, but the window doesn't move? If so, there are torque pins in the motor's drive gear that commonly break & aren't too bad to replace. See the torque pin, Steve83's Tailgate Tech, & Adrianspeeder's links below. If it makes no noise, then it's probably in the electrical system. Fireguy50's wiring diagram is linked below.

To test the electrical system, remove the access panel from inside the tailgate. Run test wires from the battery directly to the window motor connector (Yellow & red wires coming right out of the motor) to confirm that the motor works. To lower the window, it should be positive to red, & negative to yellow. Be ready for the window to move, keep hands & wires clear. Make all the connections but 1, then connect & disconnect the last wire quickly to see if it tries to go the right way. If it tries to go the wrong way, reverse the wires (This also makes it so that you can lower the window & get the tailgate open to continue testing).

A- If it runs & the window moves when wired directly to the battery, perform the following tests:

A.1- With both switches at rest, connect a tester between the positive test wire from the battery & each wire from the tailgate loom at the connector for the motor. Both should read 12v. If they do the ground is good. If they don't, refer to Fireguy50's wiring diagram linked below to trace it down, or tell us what you find.

A.2- Connect the tester between the negative test wire from the battery & each wire from the loom at the connector for the motor. The red wire should read 12v when either switch is in the down position, the yellow wire should read 12v when either switch is in the up position. If they don't, refer to Fireguy50's wiring diagram linked below to trace it down, or tell us what you find.

B- If it runs but doesn't move when wired directly to the battery, in addition to your electrical problem, the torque pins in the drive gear are probably broken too. Run the electrical tests in section "A" above, & see the torque pin, Steve83's Tailgate Tech, & Adrianspeeder's links below for the torque pin replacement.

C- If it doesn't run at all when wired directly to the battery, it sounds like it's time for a new motor. See Steve83's Tailgate Tech link below & use the info for removing & replacing the motor.



Be aware that:

-The tailgate latch switch on the driver's side seems to be a common problem, check it early. Try pushing the driver's side of the tailgate in while holding the button or key switch in the up or down position. If that makes it work, check out Steve83's "How to align a Bronco Tailgate" linked below.

-Ground for the motor connects up front, & at rest runs from there through both switches & both wires to the motor.

-When either switch is operated, 1 side's ground is disconnected & replaced by hot.

-Ground for the motor is not connected to it's case, but supplied through the wires.

-There are seperate 2 power sources & 2 fuses for positive. 1 for each switch.

-The same 2 wires are used throughout for both up & down (Polarity is reversed by the switches).

-When the tailgate is open, you have to close the driver's side latch for the window to operate. Remember to open it before closing the tailgate.



Some good resource links:

Fireguy50's wiring diagram, see post 2. Great color diagram, it makes it much easier to understand what's going on.

Steve83's Tailgate Tech. Great pics & info. Look through the entire section for the portion that applies to your problem.

adrianspeeder's pics (He's doing torque pins for a passenger window, for the tailgate you don't need to drill).

Torque pins, motors, etc.

Steve83's How to align a Bronco Tailgate

Fireguy50's Re-wire your Tailgate window switch (FINISHED) Upgrade diagram using relays.



On my truck there were multiple bad connections, so it was hard to isolate the problem. Someone before me used a ton of crimp connectors :doh0715:. Basically I ended up removing them & soldering all the connections, & eliminating the corroded plug to the motor.
 

·
Registered
Joined
·
48 Posts
Discussion Starter · #3 ·
Thanks!!!

Turns out it was a bad ground from the tailgate harness to body. Cleaned it up and Viola! :thumbup Thanks, ElKabong!!! You rule. :notworthy
 
1 - 4 of 4 Posts
Top