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Old 06-14-2011, 02:05 PM
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jbentley jbentley is offline
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Electric Tailgate Window Troubleshooting

Most everyone here has likely come to the point of cursing Jeep for making a motorized rear window that MUST be rolled down in order to open the tailgate. And isn't life grand when something in that circuit or process fails.

In troubleshooting my own tailgate window issue, I have became very familiar with how this circuit works and have copied some of my replies in other threads to here:

The number one cause of TG Window failure is a little plastic switch inside the tailgate. It serves as the Grand Central Station for all of the wires from the front dash switch, rear key switch, and window motor (see details below)

A - Main power 12v supply (always on), this is also tied to F (no-wire) via a brass plate on the switch
B - one of the 2 wire feeds from the front dash switch
C - Wire lead going to the motor actuator
D - Wire lead going to the motor actuator
E - Other of the 2 wire feeds from the front dash switch
F - See A

Here's how it works:
Using the Front Dash Switch (connections B, C, D and E)
When resting, the front switch has the two leads going to the rear tailgate window switch Fully grounded
The rear switch (when resting) connects the two feeds from the front switch leads to the actuator (B-D & C-E). As they are both grounded, nothing happens.
When you move the front switch up or down, one of the 2 leads becomes energized, thus passing a + - current to the actuator, depending if it is +- or -+ determines the motor direction (up or down).

Using the rear key switch (connections A, C, D and F)
The switch has a post that is pushed one way or the other when you turn the key in the rear lock. One way connects A-C and B-D, the other way connects E-C and F-D. Because the hot feeds are opposites (A and F), and the front switch (resting) grounds B and E, you can see how the up and down are controlled by the different +- feed to the motor.

Heres the fix:
So, your plastic switch has finally broken down.. If you've started doing your homework, you'll be finding that an OEM switch is impossible to find (discontinued) beyond one in another Jeep, which could fail at any point.
Check out this site, it gives you perfect instructions on how to modify a modern common "momentary on" (aka MOM) switch to work as a reliable and improved solution, they even give the part number of the switch!
http://www.ipendia.com/ArticleRead.aspx?id=2138
DO NOT USE THE PART NUMBER PROVIDED IN THE IPENDIA THREAD ABOVE, you will no longer be able to use the dashboard tailgate window switch if you do. Instead, order a Carlington Switch (part no 6GER5M-73) from onlinecomponents.com. These switches are manufactured on order, so it will take 5-6 weeks to arrive and cost ~$10-15 for the switch plus shipping.
EDIT:
When removing the rear key cylinder in order to remove the rear tailgate switch, you will need to do one of the following:
A. Acquire a hollow Star/Torx tool as there is a little post in the star well on the screws (using a unique tool makes it harder for the would be thief to remove your lock). Sorry, I don't know the precise size off hand.
B. Using a creative tool (I used the engraving bit on my dremel), grind down the post. Be careful not to let the tool slip around and damage the Star pattern in the screws. I figure if someone wants in bad enough to remove the lock, they'll just break a window anyway.

I also discussed with a gentleman, an issue where his rear lock switch worked in moving the window, but the front wouldn't. Here was my reply:

If your rear lock switch works, then everything inside your tailgate and wiring must be fine. In this scenario the problem has to be in the front switch itself, or the power feed to the front switch.

In order for the rear switch to work, it relies on the two wires (brown/tan most commonly) coming from the front switch being grounded and everything in the rear tailgate being in good contact. IE, your rear switch won't work without the grounded feeds from the front.

The only issue that makes since, is that when you try to use the front switch either:
A. The power feed going to the switch is dead (blown fuse possibly because this is a separate feed from the 12v that goes to the rear switch).
B. The front switch itself has failed, causing the power feed to not make contact when you move the switch up and down.

Here's how the front switch works.
Resting - Both feeds going to the tail gate are grounded.
Up - One feed to the tailgate remains grounded, the other becomes energized from the hot wire in the front switch harness.
Down - The exact same as up, except, of the two wires going to the tailgate, the hot/grounded lines are opposite from the up. What was grounded when pushing the switch UP, is now live; and what was live when pushing the switch UP is now grounded.

I would first test by pulling the wiring harness off of the front switch, you should find a single point on the harness with a red live wire coming in (or 2 wires sometimes, but they connect at the same single point in the harness), this point should be 12v.

For example, the front tailgate switch wire harness on my 82 has 2 red wires (12v) coming in to the harness at a single point.
2 black wires (grounded) coming in to the harness at a single point.
1 brown wire going to the tailgate.
1 tan wire going to the tailgate.
Giving a total of 4 separate contacts

The brown and tan wires are grounded when the switch is resting.
If I move the front switch up, one of the brown/tan wires becomes 12v live. The other one if I move the switch down.

The only exception to this, would be if the rear switch (when resting) is failing to connect the two feeds from the front switch to the motor leads (see the diagram above), but is still capable of making contact when the post in the rear switch is pushed up or down via the rear key mechanism. If all electrical troubleshooting of the front switch appears to be in proper order, then replacement of the rear switch is required, see the link above.

The key point to know here, is that the front switch has its own 12v feed, and the rear has its own separate 12v feed. Often, these are on 2 separately fused circuits, so just because one is hot, doesn't mean the other is.
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Last edited by jbentley : 08-26-2011 at 07:22 AM.
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Old 06-14-2011, 02:18 PM
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Thank you, that is a great help.
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Old 06-14-2011, 07:09 PM
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Excellent write-up...thanks !
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Old 06-14-2011, 07:31 PM
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I seem to have two separate non electrical issues.

1. Weatherstripping deterioration "gumming up" the track
(have replacement ready)

2. If the tailgate is not closed ...all the way...the motor won't activate.
It requires a mild body slam on the driver side of tailgate..and may tie in with that hook or latch by the door jamb.
Then it will slowly roll up or down with some assistance.

I've removed the panels to access the interior...but had to locate the special hollow star wrench for the key lock.

If someone has the steps written up to replace the weatherstripping, I'd appreciate the instruction.

As for the jamb...has anyone else had the same issue?

Thx
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  #5  
Old 06-15-2011, 08:50 AM
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jbentley jbentley is offline
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I can't be of much help with the weatherstripping, except for; www.teamgrandwagoneer.com has it (no special tools required) for a little more than $100. I like their WS setup because you don't need the special crimpers.

As for the Body Slam... On the driver side, near the latch, is a door safety switch (like the ones on your regular doors to turn on the courtesy lights). It's purpose is to prevent the window from being rolled up while the tailgate is down.

As of currently, I have not successfully traced out how this switch plays in to the overall wiring of the tailgate circuit, and wouldn't be surprised if somewhere along the way, someone just simply took it out of the loop; because I can activate the window motor with the tailgate down (and I shouldn't be able to do that).

Just guessing...... I would think that it interrupts one of the feeds from the front switch to prevent the window from going up, so the tailgate has to be shut in order to complete the ground circuit, not sure if it would be the brown or tan wire.

I haven't installed my new rear switch yet, so when I do, I'll check out the safety switch wiring... Looks like I might need another part (not sure on the condition of the door switch, I know my front driver and passenger door switches are busted).
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Old 06-15-2011, 09:56 AM
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serehill serehill is offline
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Bad design

I actually love the window seal design compared to all the standard windows that leak & make wind noise.
Because of the weak wiring & switches. I ripped mine out & completely rebuilt mine enlarging the wires to the rear & utilizing relays instead of the switches to carry enough current to let the motor run without unreasonble voltage drop. The original design /concept is bad. Voltage to the motor drops to less than 5 volts simply because the switches do no carry good amperage & the wiring is too small. These systems left stock will always have problems. The worst thing I did was remove the tailgate closed switch. Other than that mine works better than it ever could have stock.
The switches now just control relays. After having a friends GW get broken into by people breaking the key mechanism & jumping the wires I just removed mine. I did remove the tailgate switch,I can live with that. Compared the the crook destoying the tailgate to jump the switch. It's just he way I did it. & my opinion. There is more written about these tailgates & fixing it stock just about guarantee's it wll re occur.

Last edited by serehill : 12-18-2011 at 08:35 PM.
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Old 06-16-2011, 08:01 PM
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bruner1981jpce bruner1981jpce is offline
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Quote:
Originally Posted by jbentley

As of currently, I have not successfully traced out how this switch plays in to the overall wiring of the tailgate circuit, and wouldn't be surprised if somewhere along the way, someone just simply took it out of the loop; because I can activate the window motor with the tailgate down (and I shouldn't be able to do that).
In my tracing of wires in the tailgate, the way it ties in (for mine anyways) is the brown feed wire for the motor runs to and from the switch, so my guess is that when the tailgate is closed and the switch is properly engaged, it completes the wire. When the switch is not engaged, the wire is not complete, so in either direction, the motor is either not getting a ground or a power feed. Hope this helps
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Old 07-05-2011, 01:02 PM
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Sounds like that will let you lower the window from the driver side, but not raise it. Which makes sense, because it should already be lowered in the first place to have opened the tailgate.

Anyway, I referenced a website for modifying a modern switch to replace the factory original rear switch. However; after attempting to do this myself I came across an issue:
The replacement switch depicted on site http://ipendia.com/ArticleRead.aspx?ID=2138, is an On-Off-On style. Meaning that when in the middle position (resting) nothing is connected to the window motor, hence the front dash switch for the rear window will no longer work.

I emailed Carlington with my switch requirements and they provided me with part number 6GER5M-73, which can be ordered in single quantity from http://www.onlinecomponents.com/carl...tml?p=16992966 for about $15 and 5 weeks of patience. I'm assuming that these switches are built upon order, as even Carlington's website states 4 week wait time when you look it up via part number search. I even emailed them a drawing of how I need the switch posts to be connected, and they confirmed that the part number specified here will do the trick. I just got this info today, so I have not had an opportunity to get my hands physically on this switch and try it out.
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Old 08-22-2011, 04:05 PM
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Update:

I received the Carlington switch (6GER5M-73) today. I ordered this switch from OnlineComponents.com 6 weeks ago. The 5 week back order appears to be because the manufacturer makes these on order, but there is no minimum quantity from onlinecomponents.com.

the switch was about $10 and shipping about $15... I'm out $25 for the switch, but it is the same size as the one depicted in the Ipendia writeup and is made from metal.

So, while I have not installed it yet, this switch part number will replace the factory switch using the modifications in the Ipendia guide AND provide functionality of BOTH front and rear tailgate switches.
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Old 08-23-2011, 08:27 AM
smacaroni smacaroni is offline
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You can remove the safety torx screws with a chisel and hammer. You'll need someone to hold the swing-up cover open while you do this though. Then replace it with regular torx heads or any other screw that suits your fancy. What might be even easier yet is to find a small flat screw driver you can jam in the hole and turn it, all you gotta do is break the small amount of friction holding it in place.
I understand the anti-theft thinking, but thieves will smash a window if they want in, a strange screw won't deter them. I've even had them smash a window on an unlocked door.

Yes, the tailgate closed switch is a momentary NO switch which keeps the motor from receiving any current when the tailgate is open. You can simply jump a thick wire from one side to the other using spade terminals, but for as delicate as the glass is and as simple as the switch is, you really should keep it in place, especially if you have kids and your front switch works. If your front switch doesn't work, don't worry about it.
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Old 05-02-2012, 01:09 AM
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Thumbs up

This is great! I could use this information. My problem is that the front switch doesn't do anything and I don't have the key for the rear; the IGN and other keys were changed at some point.
Quote:
Originally Posted by jbentley
Most everyone here has likely come to the point of cursing Jeep for making a motorized rear window that MUST be rolled down in order to open the tailgate. And isn't life grand when something in that circuit or process fails.

In troubleshooting my own tailgate window issue, I have became very familiar with how this circuit works and have copied some of my replies in other threads to here:

The number one cause of TG Window failure is a little plastic switch inside the tailgate. It serves as the Grand Central Station for all of the wires from the front dash switch, rear key switch, and window motor (see details below)

A - Main power 12v supply (always on), this is also tied to F (no-wire) via a brass plate on the switch
B - one of the 2 wire feeds from the front dash switch
C - Wire lead going to the motor actuator
D - Wire lead going to the motor actuator
E - Other of the 2 wire feeds from the front dash switch
F - See A

Here's how it works:
Using the Front Dash Switch (connections B, C, D and E)
When resting, the front switch has the two leads going to the rear tailgate window switch Fully grounded
The rear switch (when resting) connects the two feeds from the front switch leads to the actuator (B-D & C-E). As they are both grounded, nothing happens.
When you move the front switch up or down, one of the 2 leads becomes energized, thus passing a + - current to the actuator, depending if it is +- or -+ determines the motor direction (up or down).

Using the rear key switch (connections A, C, D and F)
The switch has a post that is pushed one way or the other when you turn the key in the rear lock. One way connects A-C and B-D, the other way connects E-C and F-D. Because the hot feeds are opposites (A and F), and the front switch (resting) grounds B and E, you can see how the up and down are controlled by the different +- feed to the motor.

Heres the fix:
So, your plastic switch has finally broken down.. If you've started doing your homework, you'll be finding that an OEM switch is impossible to find (discontinued) beyond one in another Jeep, which could fail at any point.
Check out this site, it gives you perfect instructions on how to modify a modern common "momentary on" (aka MOM) switch to work as a reliable and improved solution, they even give the part number of the switch!
http://www.ipendia.com/ArticleRead.aspx?id=2138
DO NOT USE THE PART NUMBER PROVIDED IN THE IPENDIA THREAD ABOVE, you will no longer be able to use the dashboard tailgate window switch if you do. Instead, order a Carlington Switch (part no 6GER5M-73) from onlinecomponents.com. These switches are manufactured on order, so it will take 5-6 weeks to arrive and cost ~$10-15 for the switch plus shipping.
EDIT:
When removing the rear key cylinder in order to remove the rear tailgate switch, you will need to do one of the following:
A. Acquire a hollow Star/Torx tool as there is a little post in the star well on the screws (using a unique tool makes it harder for the would be thief to remove your lock). Sorry, I don't know the precise size off hand.
B. Using a creative tool (I used the engraving bit on my dremel), grind down the post. Be careful not to let the tool slip around and damage the Star pattern in the screws. I figure if someone wants in bad enough to remove the lock, they'll just break a window anyway.

I also discussed with a gentleman, an issue where his rear lock switch worked in moving the window, but the front wouldn't. Here was my reply:

If your rear lock switch works, then everything inside your tailgate and wiring must be fine. In this scenario the problem has to be in the front switch itself, or the power feed to the front switch.

In order for the rear switch to work, it relies on the two wires (brown/tan most commonly) coming from the front switch being grounded and everything in the rear tailgate being in good contact. IE, your rear switch won't work without the grounded feeds from the front.

The only issue that makes since, is that when you try to use the front switch either:
A. The power feed going to the switch is dead (blown fuse possibly because this is a separate feed from the 12v that goes to the rear switch).
B. The front switch itself has failed, causing the power feed to not make contact when you move the switch up and down.

Here's how the front switch works.
Resting - Both feeds going to the tail gate are grounded.
Up - One feed to the tailgate remains grounded, the other becomes energized from the hot wire in the front switch harness.
Down - The exact same as up, except, of the two wires going to the tailgate, the hot/grounded lines are opposite from the up. What was grounded when pushing the switch UP, is now live; and what was live when pushing the switch UP is now grounded.

I would first test by pulling the wiring harness off of the front switch, you should find a single point on the harness with a red live wire coming in (or 2 wires sometimes, but they connect at the same single point in the harness), this point should be 12v.

For example, the front tailgate switch wire harness on my 82 has 2 red wires (12v) coming in to the harness at a single point.
2 black wires (grounded) coming in to the harness at a single point.
1 brown wire going to the tailgate.
1 tan wire going to the tailgate.
Giving a total of 4 separate contacts

The brown and tan wires are grounded when the switch is resting.
If I move the front switch up, one of the brown/tan wires becomes 12v live. The other one if I move the switch down.

The only exception to this, would be if the rear switch (when resting) is failing to connect the two feeds from the front switch to the motor leads (see the diagram above), but is still capable of making contact when the post in the rear switch is pushed up or down via the rear key mechanism. If all electrical troubleshooting of the front switch appears to be in proper order, then replacement of the rear switch is required, see the link above.

The key point to know here, is that the front switch has its own 12v feed, and the rear has its own separate 12v feed. Often, these are on 2 separately fused circuits, so just because one is hot, doesn't mean the other is.
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Old 05-02-2012, 01:42 AM
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svining svining is offline
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Wink Easy Peasy!

I had a simiar problem...didn't know if anything worked in there. I opened the rear inspection panal with window stuck up. Used some alligator clamps and my 12Volt 6 amp charger and hooked up to the motor directly to power source.

To my surprise the motor worked fine and the window went down...reverse the wires and it went up!! With that kbnown then it was only a matter of reverse testing the system through the safety switchs to the front.

Found the problem quickly at the flex point where the wires come through the body and enter the tailgate floor. Hot wire corroded there..used a butt end connector and all the switches worked again! Still makes me happy to tell the story.




Quote:
Originally Posted by AMC80cherokee
This is great! I could use this information. My problem is that the front switch doesn't do anything and I don't have the key for the rear; the IGN and other keys were changed at some point.
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Old 05-02-2012, 07:45 AM
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Quote:
Originally Posted by AMC80cherokee
This is great! I could use this information. My problem is that the front switch doesn't do anything and I don't have the key for the rear; the IGN and other keys were changed at some point.

Once you've disassembled the rear locking mechanism, you can take the lock cylinder to a locksmith, who can re-key it to match one of your existing keys for the vehicle.
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Old 05-02-2012, 08:03 AM
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I just noticed that I never updated this thread after all that work on the tailgate...

In short, it worked like a charm! For the first time in over a decade, the rear window is functioning properly.
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Old 05-02-2012, 05:28 PM
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Thank You, Too!!!

I read your article multiple times, I felt like I knew the devil I was about to encounter. Thank-you for taking the time to document your experience.






Quote:
Originally Posted by jbentley
I just noticed that I never updated this thread after all that work on the tailgate...

In short, it worked like a charm! For the first time in over a decade, the rear window is functioning properly.
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Old 05-06-2012, 06:28 PM
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Bad Motor?

I followed this thread and others to replace the rear switch in mine with the Eaton version. Now that I have the switch wired up the motor will raise but not lower the window. We checked voltage all the way to the snap connector to the motor and got 12v with all four options (front & rear/ up & down). We then disassembled the motor and got the same (12v x 4 ways). We decided the motor must be bad, does this make sense? Where can I source a new motor? Thanks to everyone for sharing so much knowledge on this site. BTW - I started another thread about this issue but piled on here.
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Old 05-06-2012, 11:45 PM
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No it Doesn't...

The motor goes up when wires are pos/neg and when polarity reversed neg/pos it goes down, so if it works one way i can't figure why it wouldn't go with polarity reversed. same motor.




Quote:
Originally Posted by aktrapper
I followed this thread and others to replace the rear switch in mine with the Eaton version. Now that I have the switch wired up the motor will raise but not lower the window. We checked voltage all the way to the snap connector to the motor and got 12v with all four options (front & rear/ up & down). We then disassembled the motor and got the same (12v x 4 ways). We decided the motor must be bad, does this make sense? Where can I source a new motor? Thanks to everyone for sharing so much knowledge on this site. BTW - I started another thread about this issue but piled on here.
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Old 12-16-2012, 11:59 AM
CJ5 CJ5 is offline
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I put everything together in the tailgate and was checking all connections before I sign off on it. Good thing I did, prior to installing, as I seem to have an issue. I have read about everything on here so I wanted to see if anyone had an ideas for testing.

I have everything on the bench and the tailgate wiring complete and installed. I am using the wires coming out of the tailgate (no plugs installed yet where they meet the frame harness). Motor and safety switch are fine.

I tested the rear key switch first. Applied 12v to the orange wire and grounded the Tan and Brown wire. Turned key switch and get up and down movement. No problem there.

I now connect the dash switch. Connect 12v to dash switch, Leave the orange wire connect to 12v, connect ground to dash switch and connect the brown and tan wire. When I do this, I only get movement on one pole. Up or down depending on where I attach the brown and tan. Using a test light, I get 12v to both poles. So, does that mean it is a ground issue? If so, it has to be in one of the switches, right?

EDIT: I removed everything from the tailgate for further bench testing. I followed all procedures outline in the tech manual; I checked the front switch with test light both and all tests fine. I tested rear switch with test light and all test correct. I am leaning towards something with a ground maybe in the tailgate switch.??

This get's me to the problem. How can I tell which switch is bad, if either? Are there tests I can do using my meter?

Any thoughts on tests I can do?

Those who know about electrical, what would I look for if trying to find a replacement dash switch. I have several switch here and they are regular three prong. Power and two throws. The dash has those three but a fourth prong for a ground wire.


Quote:
Originally Posted by jbentley

A - Main power 12v supply (always on), this is also tied to F (no-wire) via a brass plate on the switch
B - one of the 2 wire feeds from the front dash switch
C - Wire lead going to the motor actuator
D - Wire lead going to the motor actuator
E - Other of the 2 wire feeds from the front dash switch
F - See A

Here's how it works:
Using the Front Dash Switch (connections B, C, D and E)
When resting, the front switch has the two leads going to the rear tailgate window switch Fully grounded
The rear switch (when resting) connects the two feeds from the front switch leads to the actuator (B-D & C-E). As they are both grounded, nothing happens.
When you move the front switch up or down, one of the 2 leads becomes energized, thus passing a + - current to the actuator, depending if it is +- or -+ determines the motor direction (up or down).

Using the rear key switch (connections A, C, D and F)
The switch has a post that is pushed one way or the other when you turn the key in the rear lock. One way connects A-C and B-D, the other way connects E-C and F-D. Because the hot feeds are opposites (A and F), and the front switch (resting) grounds B and E, you can see how the up and down are controlled by the different +- feed to the motor.

The only issue that makes since, is that when you try to use the front switch either:
A. The power feed going to the switch is dead (blown fuse possibly because this is a separate feed from the 12v that goes to the rear switch).
B. The front switch itself has failed, causing the power feed to not make contact when you move the switch up and down.

Here's how the front switch works.
Resting - Both feeds going to the tail gate are grounded.
Up - One feed to the tailgate remains grounded, the other becomes energized from the hot wire in the front switch harness.
Down - The exact same as up, except, of the two wires going to the tailgate, the hot/grounded lines are opposite from the up. What was grounded when pushing the switch UP, is now live; and what was live when pushing the switch UP is now grounded.

I would first test by pulling the wiring harness off of the front switch, you should find a single point on the harness with a red live wire coming in (or 2 wires sometimes, but they connect at the same single point in the harness), this point should be 12v.

For example, the front tailgate switch wire harness on my 82 has 2 red wires (12v) coming in to the harness at a single point.
2 black wires (grounded) coming in to the harness at a single point.
1 brown wire going to the tailgate.
1 tan wire going to the tailgate.
Giving a total of 4 separate contacts

The brown and tan wires are grounded when the switch is resting.
If I move the front switch up, one of the brown/tan wires becomes 12v live. The other one if I move the switch down.

The only exception to this, would be if the rear switch (when resting) is failing to connect the two feeds from the front switch to the motor leads (see the diagram above), but is still capable of making contact when the post in the rear switch is pushed up or down via the rear key mechanism. If all electrical troubleshooting of the front switch appears to be in proper order, then replacement of the rear switch is required, see the link above.

The key point to know here, is that the front switch has its own 12v feed, and the rear has its own separate 12v feed. Often, these are on 2 separately fused circuits, so just because one is hot, doesn't mean the other is.
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Last edited by CJ5 : 12-16-2012 at 12:53 PM.
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Old 12-17-2012, 09:36 AM
CJ5 CJ5 is offline
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I spend the full weekend on this and still no resolution. I am going to take the dash switch to a place in town and see if I can get some help. My electrical skills are limited. I think it could be either switch that is bad. I have a used tailgate switch I picked up from someone on the board. It looks to be in excellent condition, that is why I have not ruled it as bad just yet.

One thing that keeps getting me back to the dash switch is that it tests out very odd.

Four prongs; up, 12v, down and ground. If I measure continuity on the up prong and ground I get nothing. If I measure on the down tab and ground I get continuity. It continues with continuity even if I move the switch. That doesn't make sense to me. To me it should measure the same either way. Thoughts?
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Old 12-17-2012, 10:40 AM
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Excellent write up. My issue is that the dash switch works fine but the rear key switch does nothing which, as you can imagine is a real PITA when wanting to put say, groceries in the back after coming back to a parked and locked vehicle. Ugh!

I will try to disassemble and figure this one out this weekend. Also, my window goes up fine but on the way down it hangs up on one side (passenger) and often needs to be "pushed" in order to keep rolling down. Double PITA! But I assume that's just a weather stripping thing.
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