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Discussion Starter #1
Okay, brief synopsis:
Bought 89 Bronco from clueless PO
Discovered no motor for rear window
Installed new motor, cleaned and reinstalled lift/gear assembly.
Motor operates via relay buttons but not from front dash switch.
Disconnected wiring harness behind taillight and voltages change when front switch is actuated a d wires ohm correctly back to taillight connector.
Used 12 battery from taillight connecter to motor and used relay buttons which worked as designed but when all plugs are connected, the dash switch does not engage the motor

Question: is it possible for the relay buttons to work but the relay itself to not work from the dash switch? To reiterate, the dash switch works and correct voltages were present at the taillight using the ignition power...

Any suggestions 馃馃樀
 

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Sounds like there is no power running to the dash switch. The way the circuit is designed is that it feeds through both switches to run the motor with the tailgate switch having constant power and the dash switch getting power in Acc or Run. Does your Bronco have power windows and do they work? The reason I ask is that they are on the same circuit in the fuse panel with the dash switch power.

From Steve83's Supermotor page
154191
 

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Discussion Starter #3
I have power thru the front switch all the way to the plug behind the taillight and it changes when the rocker switch is actuated..
 

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Which color wires do you have power on without pressing the dash switch and then with pressing the switch at that plug?
 

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Discussion Starter #5
Switch ohms correctly and I have 12 volts at lb/bk with ignition on. At the taillight plug I have 12v at b/W with ignition off and 12v at P/Bl with switch on... Dash switch moves glass up but not down...
 

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In a stock 89 there are no relays for the back window. If you have them it's a modification. Where are they located? I think Fireguy had a relay mod diagram that several people used, but there is no guarantee that your PO followed it. I'll see if I can find it.
 

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Switch ohms correctly and I have 12 volts at lb/bk with ignition on. At the taillight plug I have 12v at b/W with ignition off and 12v at P/Bl with switch on... Dash switch moves glass up but not down...
Is there power with the switch activated in the other direction on the P/G? When using the dash switch it sends to either of the two purple wires depending on which direction you are pressing. Everything contact wise as far as grounding to run the motor sounds good for both switches since if either switch had a bad connection for grounding the window wouldn't work at all.

On another note, I really need to see about figuring the design again for running relays that I came up with. May try to get that worked on sometime soon and post up when I do.
 

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I struck out on that relay upgrade diagram. Maybe @miesk5 knows where we can find a copy.
Yo EL,
Here is Ryan's diagram;
154288

Ryan wrote, "
Same from 1980-1996, I can't find any 78-79 diagrams to conferm, but I'm pretty sure they are the same as well.
The defroster changed a little when the underhood fuse box was used in the 90's."
Steve wrote "
The change to the circuit actually occurred in '87 when the defrost switch moved from below the dash to within the dash. The early one was a black box with a slide lever, a green indicator, and an electrically separate blue backlight; the '87-91 style was a black rocker with an yellow indicator and a green backlight; the '92-96 switch had a chrome bar button with an orange indicator light and blue backlit letters. But the 2 later styles are electrically interchangeable.
Ryan FYI: I stole your diagrams and added them to this album...." 鈽miesk5 Note, look for the wiring diagram @ 1983 Ford Bronco Diagrams pictures, videos, and sounds | SuperMotors.net
My internet is dead slow and my vision is off today. Ensure diagrams by Ryan are compatible to your year.


.
鈻犫棌鈻
See jowens1126 diagram and narrative @ rear window need help
鈯欌棁鈯

By Steve;92-96 shown; "87-91 similar; NONE OF THESE control switch improvements (left 2 columns) will work for '78-86 Broncos due to the internal wiring of the dash switch. The simplifications, indicator lamp, & 1-touch WILL work on '78-96.

154289


The factory circuit passes full current through 4 terminals of BOTH switches every time the window is used, resulting in high resistance & slow window movement. The modified circuits:
  • reduce the current passing through the switches (making them last longer);
  • replace the special switches with 2 common relays (making them easier to replace if they ever go bad);
  • allows any number of additional switches with no degredation in performance;
  • uses the factory wiring & circuit breakers, and requires NO new wires through the tailgate hinge (for most trucks). If the truck doesn't have a factory defrost ground wire, then one heavy ground must be added from the body inside the L taillight well to the tailgate relays & switch.
The Improved (Ground-Switched) Circuit has the benefits of converting to always-on, and having no hot wires strung through the truck. This is the best way to add switches &/or improve t/g window function.

The Hot-Switched circuit has the benefit of being simpler to rewire. But the grounds MUST be removed from the dash switch connector, and a fused hot wire must be strung to each new switch location."
 

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Discussion Starter #11
If I input 12v at the dash plug on P/Bl and P/g I can I can run the window up and down but only one direction using dash switch and ignition power. The switch ohms correctly.
 

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Tater I feel your pain , after many years dealing with this highly resistive circuit , I chose the hot switched circuit .I installed two relays(behind drivers tail rear lens ),rewired per print . This worked great and NO MORE TROUBLE WITH MY REAR WINDOW!!!!!!!! plus ,I can use the dash switch w/o inserting the key. If switches weren't failing the motor was slow and weak. Good luck TR
 

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Discussion Starter #14
Finally...the dash switch was bad... My son noticed a bent contact and straightened it with a pair of needle nose pliers and I'm good to go..

Next, somebody tel me where the bottom end of the latch control rod attached. Seems the torsion bar is the only choice but if so, how is it connected?
 

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-90 xlt, 351w, e4od, man 1356, 3.55, sag, warn hubs, 35s. -73, 400, np435, d20j twin, 35s
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I haven't worked on one, but I thought it was just sort on an L shaped hook end on the bottom that stuck out in the path of the window. @BikerPepe` has worked on those, may be able to answer your question, & has a good routine for removing them.
 

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'95 XLT: 5.8, MAF, E4OD, 4.56's, 6" lift on 33's
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What Mikey350 says is true and it's just good stuff to know as a Bronco owner.

The rod you're questioning is usually held in place by a plastic clip. The rod catches the bottom lip of the window as it goes down and when it's fully down, the rod pulls a latch on the tailgate handle, allowing it to operate/open. The safety feature can be over-ridden by brute force but repeated abuse will bend bend parts of the tailgate handle assembly until it no longer works.

I chose to remove the rod and the latch from the tailgate handle assembly. It's easy to do, if you'd like but not necessary. If you go through Steve83 info, as suggested... you should be able to find where that little clip that holds the rod in place is. I can't give you a pic because I removed it. It's pretty much straight down, about 1/2 way to the bottom.

You're choice in how you want to handle it.
pun intended. ;)
 
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