Back window/latch issue 79 bronco

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Melmac39

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I see posts about 80’s back window and not sure they apply to 78-79. Here’s my problem, back window did roll down, then wouldn’t roll up. Likely because my brother didn’t roll all the way down. Now the tailgate doesn’t latch as tight as previously did and window not working. When jumping the window, motor works. What can I do to fix this? I now have window up.
 

miesk5

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Yo,
Latch Safety Switch (also ref to as Limit Switch or Interlock Switch); "...miesk5 Note; In 78-82, both latches have to be closed since the interlock safety switch is mounted in the center mechanism; & their strikes that mount to the body can be interchanged with some effort. The safety switch was moved from the center (tailgate handle) to the left latch by 1983 by Seabronc (Rosie, Fred W)

If the latch doesn't lock, try to get it to latch with the t/g down and use a screwdriver (or something slightly smaller than the strike post) to close the jaws. You probably just need to rinse it out with Liquid Wrench (not WD-40; too much wax) or some other penetrating oil. If it still won't latch, put the glass up & pull the access panel. Inspect the operating rod that runs from the center mechanism to that latch to make sure it's not bent, keeping the latch released. If the rod is SLIGHTLY slack and the latch is clean & lubed, but won't catch, replace the latch.

If it latches with the t/g open but not EVERY time that you close it, trace a circle around the big washer (for reference) and then shift the strike post rearward ~1/32" at a time until it latches or you've gone 1/4". If it still won't latch, then you need to move the post up or down to align it.

"...The safety switch was moved from the tailgate handle to the left latch by 1983..." per Seabronc; 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 on 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 at that switch. Ground for the motor is not connected to it's case, but supplied through the wires. The 78-79 TG ckt included a 20 a Circuit Breaker @ starter relay & receives 12 v from Ignition Switch; whereas later years don't have the CB there; it is of course in the Fuse Panel or have 2 fuses in the panel; & Relay Location in 78-79; for the 78-9 People, for us, it is quite easy, under the dash behind the instrument cluster, there is a relay, that relay is to run the main constant power for the rear window when the key is on,by origin at FSB; Relay Location in 78-79; Behind the guage/speedo is a relay that powers the inside switch, check it, by Zebrafive at FSB;
Testing: Does motor 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 & Adrianspeeder's links. If it makes no noise, then it's probably in the electrical system.

Sometimes the connector for the tailgate motor will test ok, but not make contact when plugged in.
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.

If motor 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. .."
 

johnnyreb

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I see posts about 80’s back window and not sure they apply to 78-79. Here’s my problem, back window did roll down, then wouldn’t roll up. Likely because my brother didn’t roll all the way down. Now the tailgate doesn’t latch as tight as previously did and window not working. When jumping the window, motor works. What can I do to fix this? I now have window up.
About the only way find out all the problems and its age. You will find them. When you take it apart. Their might be some parts rusted out. Not allowing window to line up and operate easy. You,ll more the likely find wires needing attending to. Getting a good ground.bad switch. Good luck and welcome to the club.
 
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Melmac39

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Thanks everyone! I this forum is such a great resource. All of your time and help is very much appreciated. It seems I have some greasing, grounding, and troubleshooting ahead of me for the weekend.
 

johnnyreb

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Thanks everyone! I this forum is such a great resource. All of your time and help is very much appreciated. It seems I have some greasing, grounding, and troubleshooting ahead of me for the weekend.
Glad you found some help. Before you put everything back together. You might want to consider cleaning up INSIDE THE TAILGATE. T o help prevent rust from starting around the lower part and get some new outside seal around all the window and tailgate.Plus get a impact ***** driver. The heavy duty type you hit with a hammer. To loosen the adjustments screws on the hinges and the latch parts.
 

johnnyreb

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Yo,
Latch Safety Switch (also ref to as Limit Switch or Interlock Switch); "...miesk5 Note; In 78-82, both latches have to be closed since the interlock safety switch is mounted in the center mechanism; & their strikes that mount to the body can be interchanged with some effort. The safety switch was moved from the center (tailgate handle) to the left latch by 1983 by Seabronc (Rosie, Fred W)

If the latch doesn't lock, try to get it to latch with the t/g down and use a screwdriver (or something slightly smaller than the strike post) to close the jaws. You probably just need to rinse it out with Liquid Wrench (not WD-40; too much wax) or some other penetrating oil. If it still won't latch, put the glass up & pull the access panel. Inspect the operating rod that runs from the center mechanism to that latch to make sure it's not bent, keeping the latch released. If the rod is SLIGHTLY slack and the latch is clean & lubed, but won't catch, replace the latch.

If it latches with the t/g open but not EVERY time that you close it, trace a circle around the big washer (for reference) and then shift the strike post rearward ~1/32" at a time until it latches or you've gone 1/4". If it still won't latch, then you need to move the post up or down to align it.

"...The safety switch was moved from the tailgate handle to the left latch by 1983..." per Seabronc; 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 on 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 at that switch. Ground for the motor is not connected to it's case, but supplied through the wires. The 78-79 TG ckt included a 20 a Circuit Breaker @ starter relay & receives 12 v from Ignition Switch; whereas later years don't have the CB there; it is of course in the Fuse Panel or have 2 fuses in the panel; & Relay Location in 78-79; for the 78-9 People, for us, it is quite easy, under the dash behind the instrument cluster, there is a relay, that relay is to run the main constant power for the rear window when the key is on,by origin at FSB; Relay Location in 78-79; Behind the guage/speedo is a relay that powers the inside switch, check it, by Zebrafive at FSB;
Testing: Does motor 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 & Adrianspeeder's links. If it makes no noise, then it's probably in the electrical system.

Sometimes the connector for the tailgate motor will test ok, but not make contact when plugged in.
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.

If motor 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. .."
I didn,t know this until the other day. Correct me if I am wrong,but I think their is a switch--when the tailgate is laying down. Prevents the window from working--so the window won,t get broken. I was tinkering on mine the other day and when I started putting things away. I thought I,d hit the dash switch and roll the window up. Nothing happened .Then I turned and noticed my tail gate down. I got out closed it and the window went up.
 
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Melmac39

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You are right. It’s an attempt by Ford back then to restrict using the window and tailgate when it’s half way down. At least that is what I’m being told. No that I have the window up I’m debating if I should just order all the new parts and wiring to eliminate this happening in the future. I have 12V all the way to the motor, my hang up now if that the latch bushings are out of alignment and TG won’t close tight. That messes with the safety switch of course and the rattle is super annoying. I ordered new latch bushings but not in stock. I may just put some PE’x on them until they are off back order to tighten things up. What you guys think? Order new components or just clean up what’s there? This is all a learning process for me so while learning I want things to be correct and last as well
 

johnnyreb

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Well I,d try to clean it up and find out what all is bad,. Then I would try to fix what I could. The wiring is color coded. Get a tester to. They don,t cost,but a few dollars. Read about them . Test the wires with and without the switch on--either direction--acc or run and you learn more then you think. Also on the wires. I got me some male and female connectors . I started using them and if you need to work on them again. Its easier and get some GOOD ELECTRIC TAPE-NOT THE CHEAP TAPE. Sounds like you are willing and you learn. People hear will help you. Good luck.
 

johnnyreb

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Thank you very much for the advice!
If you have a phone that takes pictures--before you take anything apart--take a picture. That way you will know what goes where. Just take you time and you,ll learn and do good. Any questions? Their is people hear that will help you.Good luck
 

miesk5

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Yo M,
Sorry, missed seeing your question.
But what you can afford and gather parts from yard queens.
To add a simple self-diagnostic capability, wire a 12V lamp (incandescent - NOT LED) across the safety switch terminals, and mount it in the tailgate shell above the lock cylinder in the inside sill (through a carpet retainer hole if present). If either control switch is activated, and the only thing preventing the glass from moving is the safety switch, the lamp will light and be visible to a person using either switch.
latchindicator.jpg . latchlighu.jpg
 

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