3- How do I fix my back window?
The stuff below is mostly cut & paste from earlier replies, but it covers a lot of tailgate window stuff. Use what applies to your situation. To bypass everything & get it closed or open, see section A.1 below. For a list of possible causes based on your symptoms, see Table D below.
Be aware that:
-The tailgate latch switch on the driver's side seems to be a common problem, check it early. It keeps the window from being moved when the tailgate is open, & if not latched right, it'll keep the window from working at all. Try pushing the driver's side of the tailgate in while holding the dash switch or tailgate key switch in the up or down position. If that makes it work, check out Steve83's "How to align a Bronco Tailgate" link in #6 below & JKossarides info on door striker bushings in link #7 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 at that switch.
-Ground for the motor is not connected to its case, but supplied through the wires.
-There are 2 separate power sources & 2 fuses/circuit breakers 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, for testing purposes, you have to close the driver's side latch for the window to operate. Remember to put the window down & open the latch before closing the tailgate.
Testing:
If it works in some directions but not others see table "D" below before performing tests. Sometimes the symptoms can lead you to the probable cause. It is best to test to confirm before replacing parts, but the symptoms can narrow down where to test.
Does it make any noise at all? Like the motor's turning, but the window doesn't move? Will the window roll up with help? 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 you keep your hands clear, sometimes you can manually "help" the window close while someone runs the motor. If it makes no noise, then it's probably in the electrical system. Fireguy50's wiring diagram is linked below.
A.1- To test the electrical system (And to move an inoperable window), 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 method also makes it so that you can lower the window & get the tailgate open to continue testing, or close the window to temporarily get through bad weather).
If it runs & the window moves when wired directly to the battery, perform the following tests:
A.2- With both switches at rest & the driver's side tailgate latch switch closed*, 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.
*To close the driver's side tailgate latch switch for testing with the tailgate open, use a screwdriver or similar tool to close the clamshell latch. Each half of the latch has a couple of clicks. On mine it seems like both halves of the latch need to be closed evenly for it to work. Remember to open it using the inside handle before closing the gate.
A.3- With the latch switch closed, 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.
A.4- If everything tests ok, but it still doesn't run, there's a couple more possible causes to check:
-Sometimes the connector for the tailgate motor will test ok, but not make contact when plugged in. You might try backprobing the motor side wires with the plug connected. On mine I removed it & soldered the connections.
-It's possible for a damaged wire to carry enough load to show 12v on a tester, but not enough to operate the motor. Look for worn areas, especially in the loom between the body & the tailgate. A worn switch can also show those symptoms.
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.
Table D-If it works in some directions but not others:
Take a look through the combination of symptoms listed below for a list of possible causes. Test the components to confirm. This section is new & I'll continue to revise & clarify it as time allows. If you find something that is missing or needs to be tweaked, please let me know.
D.01
Yes -Dash switch up
Yes -Dash switch down
Yes -Key switch up
Yes -Key switch down
- All is good. Why are you here? :toothless
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D.02
No --Dash switch up
Yes -Dash switch down
Yes -Key switch up
Yes -Key switch down
Possible causes:
- Bad dash switch up side hot contact. Since it works for down at the dash switch & both directions from the key switch, you know that the wiring between switches, key switch ground/pass thru contacts, tailgate safety switch, & motor are all working. Since it works for one direction from the dash switch, you know you have power to the dash switch. Since it works in both directions from the key switch, you know you have good power & contacts at the key switch, good ground to the dash switch, & good ground contacts thru the dash switch. All that is left is the up side hot contact in the dash switch.
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D.03
Yes -Dash switch up
No --Dash switch down
Yes -Key switch up
Yes -Key switch down
Possible causes:
- Bad dash switch down side hot contact. Since it works for up at the dash switch & both directions from the key switch, you know that the wiring between switches, key switch ground/pass thru contacts, tailgate safety switch, & motor are all working. Since it works for one direction from the dash switch, you know you have power to the dash switch. Since it works in both directions from the key switch, you know you have good power & contacts at the key switch, good ground to the dash switch, & good ground contacts thru the dash switch. All that is left is the down side hot contact in the dash switch.
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D.04
No --Dash switch up
No --Dash switch down
Yes -Key switch up
Yes -Key switch down
Possible causes:
- No power from the fuse/circuit breaker. The dash rocker switch &tailgate key switch each has a separate power source & its own fuse/breaker. Check the fuse/breaker for the dash switch.
- Bad dash switch hot contacts. Since it works from the key switch, you know that the wiring between switches, key switch, tailgate safety switch, & motor are all working.
- Bad hot wire to the dash switch.
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D.05
Yes -Dash switch up
Yes -Dash switch down
No --Key switch up
Yes -Key switch down
Possible causes:
- Bad key switch hot contact. Since it works for up & down at the dash switch, you know that all the wiring, dash switch, key switch ground/pass thru contacts, tailgate safety switch, & motor are all working. Since it works for one direction from the key switch, you know you have power to the key switch.
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D.06
Yes -Dash switch up
Yes -Dash switch down
Yes -Key switch up
No --Key switch down
Possible causes:
- Bad key switch hot contact. Since it works for up & down at the dash switch, you know that the wiring between switches, dash switch, key switch ground/pass thru contacts, tailgate safety switch, & motor are all working. Since it works for one direction from the key switch, you know you have power to the key switch.
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D.07
Yes -Dash switch up
Yes -Dash switch down
No --Key switch up
No --Key switch down
Possible causes:
- No power from the fuse/circuit breaker for the tailgate key switch. The tailgate key switch has a separate power source than the dash switch.
- Bad hot wire to the tailgate key switch.
- Bad key switch hot contacts. Since it works for up & down at the dash switch, you know that the wiring between switches, dash switch, key switch ground/pass thru contacts, tailgate safety switch, & motor are all working.
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D.08
Yes -Dash switch up
No --Dash switch down
Yes -Key switch up
No --Key switch down
Since it works for one direction at the dash switch, you know that the wiring between switches, dash switch power, key switch ground/pass thru contacts, tailgate safety switch, & motor are all working. Since it works in one direction from the key switch you know that power to the key switch is good. A bad ground contact in the dash switch would cause both switches to quit working in one direction.
Possible causes:
- A bad ground contact in the dash switch.
- A bad hot contact in the dash switch & a bad hot contact in the tailgate switch at the same time. This seems less likely, but it is possible.
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D.09
No --Dash switch up
Yes -Dash switch down
No --Key switch up
Yes -Key switch down
Since it works for one direction at the dash switch, you know that the wiring between switches, dash switch power, key switch ground/pass thru contacts, tailgate safety switch, & motor are all working. Since it works in one direction from the key switch, you know that power to the key switch is good. A bad ground contact in the dash switch would cause both switches to quit working in one direction.
Possible causes:
- A bad ground contact in the dash switch.
- A bad hot contact in the dash switch & a bad hot contact in the tailgate switch at the same time. This seems less likely, but it is possible.
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D.10
Yes -Dash switch up
No --Dash switch down
No --Key switch up
Yes -Key switch down
Possible causes:
- This sounds like multiple problems. Probably a bad hot contact in the dash switch & an opposite bad hot contact in the tailgate switch. Since it works for one direction at the dash switch, you know that the wiring between switches, dash switch power, key switch ground/pass thru contacts, tailgate safety switch, & motor are all working. Since it works in one direction from the key switch you know power to the key switch is good.
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D.11
No --Dash switch up
Yes -Dash switch down
Yes -Key switch up
No --Key switch down
Possible causes:
- This sounds like multiple problems. Probably a bad hot contact in the dash switch & an opposite bad hot contact in the tailgate switch. Since it works for one direction at the dash switch, you know that the wiring between switches, dash switch power, key switch ground/pass thru contacts, tailgate safety switch, & motor are all working. Since it works in one direction from the key switch you know power to the key switch is good.
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D.12
Yes -Dash switch up
No --Dash switch down
No --Key switch up
No --Key switch down
This sounds like multiple problems. Since it works for one direction at the dash switch, you know that the wiring between switches, dash switch power, key switch ground/pass thru contacts, tailgate safety switch, & motor are all working.
Possible causes:
- A bad hot contact in the dash switch & no power from the breaker to the tailgate switch.
- A bad hot contact in the dash switch & bad hot wire to the tailgate switch.
- A bad hot contact in the dash switch & bad hot contacts in the tailgate switch.
- A bad ground down contact in the dash switch & a bad hot up contact in the key switch.
- A combination of the above problems.
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D.13
No --Dash switch up
Yes -Dash switch down
No --Key switch up
No --Key switch down
This sounds like multiple problems. Since it works for one direction at the dash switch, you know that the wiring between switches, dash switch power, key switch ground/pass thru contacts, tailgate safety switch, & motor are all working.
Possible causes:
- A bad hot contact in the dash switch & no power from the breaker to the tailgate switch.
- A bad hot contact in the dash switch & a bad hot wire to the tailgate switch.
- A bad hot contact in the dash switch & bad hot contacts in the tailgate switch.
- A bad ground up contact in the dash switch & a bad hot down contact in the key switch.
- A combination of the above problems.
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D.14
No --Dash switch up
No --Dash switch down
Yes -Key switch up
No --Key switch down
This might be multiple problems. Since it works for one direction at the key switch, you know that at least one wire between switches, key switch power, tailgate safety switch, & motor are all working.
Possible causes:
- A bad up ground contact in the key switch.
- A bad wire between switches.
- A bad hot contact in the key switch & no power from the breaker to the dash switch.
- A bad hot contact in the key switch & a bad hot wire to the dash switch.
- A bad hot contact in the key switch & bad hot contacts in the dash switch.
- A bad ground down contact in the dash switch & a bad hot up contact in the key switch.
- A combination of the above problems.
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D.15
No --Dash switch up
No --Dash switch down
No --Key switch up
Yes -Key switch down
This might be multiple problems. Since it works for one direction at the key switch, you know that at least one wire between switches, key switch power, tailgate safety switch, & motor are all working.
Possible causes:
- A bad down ground contact in the key switch.
- A bad wire between switches.
- A bad hot contact in the key switch & no power from the breaker to the dash switch.
- A bad hot contact in the key switch & a bad hot wire to the dash switch.
- A bad hot contact in the key switch & bad hot contacts in the dash switch.
- A bad ground up contact in the dash switch & a bad hot down contact in the key switch
- A combination of the above problems.
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D.16
No --Dash switch up
No --Dash switch down
No --Key switch up
No --Key switch down
Nothing works. Might be easy. Might be the hardest to diagnose. If it isn't one of the easy steps, good testing with a meter will pay off on this one. This is what my Bronco started with, so the testing in "A" above is based on not having any operation at all to help pinpoint the problem.
Possible causes:
- Tailgate safety switch out of adjustment or missing the bushing. Try pushing in on the driver's side of the tailgate while operating either switch. If that works, look to tailgate alignment, bushing replacement, or latch switch issues.
- Bad fuse/circuit breaker to both switches.
- Bad tailgate safety switch.
- Bad connector to the motor.
- Broken wire(s) between switches. The loom between the body & tailgate is a likely place for wear to cause this.
- Bad ground to the dash switch. This provides ground for all functions.
- Bad ground/pass thru contacts on both sides of the key switch.
- Bad ground contacts on both sides of the dash switch.
- One bad ground contact in both the dash switch & the key switch on opposite sides of the circuit.
- Bad motor.
- Bad hot contacts on both sides of both switches.
- A combination of multiple problems.
Some good resource links:
1-
Fireguy50's wiring diagram. Great color diagram for 80-96s, it makes it much easier to understand what's going on. NOTE: Fireguy's original diagram appears to be gone at this time, but
Steve83 has a copy here on his Supermotors. Thanks Steve. :thumbup
2-
Steve83's Tailgate Window Motor Circuit -Wiring diagram for 92-95s, laid out on a Bronco sketch to show locations of the various components.
3-
Tailgate WIndow Wiring Diagram miesk5 provides a diagram for 78-79s by the ORC Staff at ford.off-road.com in post 3
4-
Steve83's Tailgate Tech. Great pics & info. Look through the entire section for the portion that applies to your problem. The 1st pic explains testing for the dash switch. Almost to the bottom of the page is a method to bypass the dash switch & test the rest of the components. Click on any pic for a larger version.
5-
adrianspeeder's pics (He's doing torque pins for a passenger window, for the tailgate you don't need to drill).
6-
Torque pins, motors, etc. Sixlitre gives the torque pin part number in post 14.
7-
Steve83's Bronco Tailgate Alignment
Looks like that ^ link may be goofy. Here's the Wayback Machine version:
Bronco Tailgate Alignment
8-
JKossarides' info on replacement striker bushing numbers & wiring harness issues -See post 3.
9-
Fireguy50's Re-wire your Tailgate window switch (FINISHED) Upgrade diagram using relays.
10-
rear window switch replacement / upgrade! 87-91 Dash switch replacement info from
@Dan90FSB in post 1 &
@sackman9975 in post 7.
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. At that point it tested fine to the factory connector to the motor, but it still wouldn't run when plugged in. That final connector looked ok, but was barely corroded enough to prevent good contact. I eliminated that plug to the motor & finally got it working.
That's when I finally earned my Tailgate Window Repair badge. My mom sewed it on my sash. It was a proud moment. :toothless