Well i spent the night going through the forum so that i wouldn't waste time.First I got a jumper wire and tried to jump the rear window motor right from the two wires coming from the motor and nothing happened
so I checked with a multimeter and have volts at the end of my jumper wire.So I took it(old motor) out of the truck and tried touching the motors wire directly to the battery while holding the motor against the radiator support to hopefully offer some ground, and nothing. So I figured I should check the new one before I try to put parts of myself back in that little space. So I tried touching the wire from the motor directly to the battery, motor grounded against the support approach, to the jumper wire with motor against the bracket( to hopefully ground it out) and still nothing. So I figure it gets grounded out by being attached to the truck! Right? So I put the new motor in the truck, bolted it down and tried to use my jump wire and nothing. Bad motor? Help I checked my switches, pushed on the corner of the door etc before trying to jump. If the motor is bolted in the truck it is grounded right? And the two wires from the window motor are hot up window and down window right? So I take the hot side of the battery and run a wire of it and touch it to either of the two motor wires and something should happen if the motor is good right? Becouse I am by passing all the other possible electrical problems right?
Well thank you
Steven

 

Have you checked the switch that's inside the tailgate on the left side that detects when the tailgate is open/closed? If that switch goes bad or is misaligned, the window motor won't operate. I removed the switch and jumpered the connector to itself on mine.

 

I thought my rear window motor was bad and checked
everything out, and everything seemed to be fine, but
the window still wouldn't raise up or down. I pressed
real firmly on the tailgate standing outside of it, and it
pushed in just a little bit and that got it to work,
guess the switch wasn't making a complete connection.

I found this on the site search, hope it helps and you
get your window working.

-----------------------------------------
One thing to check is that with most power window motors you have 3 wire running to it for power. At not in use position on the switch, you will have power running to only 1 wire and the other 2 will be grounded. When you hit the down, the you will have 2 wires with 12 volts and one ground, then when going up, the wire that is ground and the new wire with 12 volts, will switch position. All you are doing is switch the polarity of the input. One way goes up the other reverses the motor to run it down. All 3 must be hooked up for it to work properly.

 

I posted the same question a couple weeks ago, and turns out the 'gate just wasn't closed all the way

 

And both of your posts point to what a pain that switch is that I'm talking about. I just bypassed mine.

 

actuaal your window motor has two wires going to it . the truck body is not used as a ground on power windo motors. depending on which way you push the switch one wire is hot and the other is ground,and when you change motor direction the polarity to these terminals will reverse.if you have already grounded the case and applied power to the terminals you may have repolarized the motorand it will operate bacwards.
take your motor and touch pos itive power to one terminal and ground the other terminal and the motor should work in one direction,now reverse your connections and the motor should turn the other direction. when you said the rear window didnt work was it not working with either the dash switch and the key switch or was it just the key switch. if just the key switch then open the tailgate and on the driver side you will see a harness going into the gate, there is a wire that feeds constant power to the key switch and that wire is prone to breakage. if it is not broken then i would bet that your safety switch is bad or misadjusted.

 

Hey Guys.....Sounds to me like he is way beyond the safety switch. He is talking about applying power to the motor directly.

loquito:
The motor works on switched polarity... Ground to one wire and power to other makes it go up. Switch the wires and it will go down. From what I read in your original post, you are trying to apply 12 volts to one wire at a time and using the motor body as ground. Make sure you try it like I mentioned above. If your old motor still works, then here is a link to the wiring schematics that may help....post again in here if you need anything else. Click on the link at the bottom of the image to enlarge it.



Bronco Tailgate Wiring

 

thank you billybob69 im glad that there is someone else that really understands the way that these motors work . i dont know if you read my post just before you or if we were both on at the same time.

 

LMAO!!! I guess we posted at the same time...
BOJOFASO!! Quit stompin on me!!! SHeesh I still have the tread marks from you shoes! hehe

 

Hey you guys are quick and right on the money, My old motor test out great. And yes I am well past the safety switch lean on the back door faze. I started another post a copy is at the bottom of this. I reposted after reading you guy's recent post and want to get more thoughts on my new problem, so far your advise has been perfect
Thank You
greasy and warm in AK
Steven

my bronco's rear window again thread

Okay so my rear window motor is just fine, I jumped it of the battery and she works perfect. So I climed into the back and used my multimeter to check the incoming wires and with the dash switch pressed I got a reading of 14 plus volts. Now here is the part that I don't get, I stripped the wire to remove the conectors at the end of the incoming as well as the motors leads. I put the two sets of wires together and I get nothing. So I took the wires apart and rechecked the incoming with dash switch pressed and got good volts. So with the two red wires attached and the yellow not attached I tested from the incoming yellow to the adjoined reds and got 14 volts, BUT as soon as I touch the two yellow together I loose my Volts. They drop down to like 1 volt.
So the motor works staight from the battery
With the motor not attached I get 14 volts to the tailgate with dash switch pushed
Attach motor wires to supply wires and Volts go away?????????????Yes with switch at dash pushed!
So what gives, I am so confused.
Obviously since I have pwer all the way back to the rear conector, the switch on the dash as well as the safety switch on the rear tailgate work fine.
The motor works fine from the battery.
Why are the two not compatible what is cousing the voltage drop when I put the two together?
Thank You
Steven

 

Give me a bit...I am gonna need to check what you did against the wiring diagram

 

Hey billybob
I don't think I did anything to the wireing. I just disconected the motor, verified it DID work with a Jumper. Verified that there was voltage at the conection coming to the tailgate from the switch.
But with the multimeter on the two truck wires I get 14 volts, with the multimeter still attached to the trucks wires I attach the motors wires and all the volts disapear, This is ofcource with the switch pushed in all during testing thus giving me the 14 volts when the motor wires are Not attached. So everthing from the switch on the dash to the last connector in the tailgate work and read 14 volts no load. The motor works if I supply direct power from the battery. But when I put the two connectors together with the multimeter showing 14 before they touch, the volts just dissapear. Nothing wireing has changed, still pushing the switch, but when i attach red to red and yellow to yellow the volts go away

 

Sorry didnt mean to make you think that I thought you changed the wiring. Now when you say the last connector at the tailgate...which one? There is one just inside the fender at the tailgate. The wiring that runs along the edge of tha tailgate is known to get a broken wire here and there from the bending. If you mean INSIDE the tailgate itself...I would still check the wiring that runs along side the tailgate that joins the tailgate to the connector just inside the fender. Could be a short in there. Just cut off the shielding and check the wires. Also make sure that there is good contact at the connectors themselves. Could be dirty or corroded. Mine had that problem with that connector in the fender at the tailgate, so I cut off the connectors and used my own quick disconnects, crimped them on, plugged em together, and wrapped in tape. If I ever need to disconnect to remove the tailgate...no prob. I also found a broken wire in the loom that runs along the edge of the tailgate.

 

Did you see my reply to your other post? The voltage will be coming in on the connector behind the left taillight, but the GROUND for both switches goes through the dash switch, this switch gets the most wear and tear. I've had to change it on both mine after doing the same things you've done.

I can sell you a tailgate harness if you like, but try the dashboard switch first!

 

Hi I am talking about the conector in the middle of the tailgate that the motor wire connect into. I am going to check the wires and switchs/connections over my weekend. I get the resistance under load idea, so I'll be checking all. Any good stock wiring diagrams for the window. switchs,fuses etc. I didnt take any offence about the wiring, I am just trying to convey the wires are still the way ford made them, Thanks for all the ideas so far, so far one returned 90 dallor motor due to advice from here.
Thanks everyone
Steven