We ditch our 86 that had huge holes in the body and a bent valves for a real nice single owner 87 with a new 22RE block and a body that is sanded and prepped for painting.

The rear window was rewired to a switch on the dash and wasn't working. I gutted all the impromptu wiring and check the rear window motor with the battery. It goes up and down, no problem.

I looked through the tailgate and found a bunch of disconnected wires from the motor. I plugged it all back together and still nothing.

Back into the tailgate I found the following two wires and I have no idea where they go or what they are





Thanks for your help!

ara

 

Are the 2 wires both solid colors from the picture the look to be red and black??

I am stuck till I know the colors for sure then I can tell you.

 

@wyoming9

Sorry! They are red and black. I am currently poking through the FSM to see if I can find out anything.

I am moderately cursing out the person that rigged up the dash switch. So much chopped wire and random bits everywhere.

 

Black and Red wires do not belong on rear window wiring (schematic's on my build thread).

Those look like wires for rear window defogger. Found same in my tailgate. If you don't use your rear defogger, I suggest you insulate those wires to make sure nothing shorts out. IIRC, rear defogger relay is also next to rear window control relay module behind B pillar, near driver's seat belt mechanism (Also on my rear window post).

 

@RAD4Runner

Awesome! Thank you. I haven't dug into the relay by the seatbelt yet. Something I was trying to avoid given that it's around a 100 here right now.

But I will go poke around.

Trying to get the window fixed before Sunday.

ara

 

NP.

You'd wanna access wires that connect to various tailgate sensors and glass position switches.

Verify that all wires go where they're supposed to go on the wide white connector that plugs into window control relay.

Keep connector disconnected from relay module, use ohm-meter to verify that each sensor/switch works. They should change states (open or close) with glass up/down, tailgate open/closed.

Then, test (UP/Down) switch inputs (pins 5, 4, 11 & 12) by jumping one at a time (individually) directly to ground.

 

Ok here is what we have so far.

Window is up and tailgate is locked

Rear window motor - Is good
Fusible link - good
Circuit breaker - good
ENGINE fuse - good
Up/down switch - good
Unlock warning switch - good

 

So to get at that relay I take it the back seat has to come out?

 

Nope, just the side panel. Rear window control relay module and rear defogger relay are here:


Once you verify wiring is good, and all connected back, test by:
Jumping wires connected to pins 5, then 4 one at a time, directly to chassis ground. These are inputs from console switches. They will only work IF and only IF ignition is on.

Then try pins 11 & then 12, one at a time, directly to to chassis ground. These are inputs for tailgate key switch and will work EVEN IF ignition were off.

Above tests will not depend on whether top is off or not.

Best of luck.

 

I just noticed that I don't have a window limit switch anywhere in my tailgate. I searched the whole right side (I am working on the inside looking out) for the switch and wiring, none of it is there.

 

Updates:

I tested the wiring harness side of things and that all passes. Except for the window limit switch test which fails due to it being missing as far as I can tell.

Jumping the relay
pin 5 to ground - nothing
pin 4 to ground - nothing
pin 11 to ground - nothing
pin 12 to ground - nothing

tested my ground connecting on the relay wiring harness - ok

repeated pin jumping to ground - nothing

 

So is the thing in the red box the window limit switch? It has a white plug but it's in the wrong place according to the '88 FSM. 87 placement different?

Another note:
I can't unlock my tailgate from inside anymore. I reattached the lock button to the locking mechanism and I can't move it now.

 

not sure if you checked this or not but there is a switch that is activated by a bolt that holds down the rear shell/canopy or whatever it's called(brainfart). I believe it is on the drivers side two or three in from the back. if you are using stock wiring make sure that switch is activated or rewire to bypass.

 

@Motox711
I found that switch by accident last night and I did test it! One of those happy accidents stumbling around the back.

 

Here is a closeup up of what I think is the limit switch?

 

Well borrowed a working relay. Nothing changed! Still no movement on the window.

I am guessing maybe the PO cut the power line somewhere for some reason???

Or the window limit switch???

 

It's the window limit switch!!!

Continuity in both positions which is bad.

Took awhile to realize that the switch is upside down and backwards from the FSM picture.

Going to figure out how to get it out... Looks like a pain.

 

UPDATE

Scratch that. Window limit switch works fine. Had trouble reading the backwards diagram for it.

I plugged a 12V light into the line coming into the motor and got nothing on it when I pushed the up and down button with the IG on.

I am guessing a cut line.

I checked all the fuses yesterday but I am going to go through them again today.

 

Ok, finally found at least one thing.

Window lock switch -> no continuity across 1-3 pins on either position
Free position -> continuity across 2-4
Locked position -> no continuity across 2-4

Bad switch???

 

Yeah, that's the "cover top" switch in schematic ^^. It should be closed when top is on and you have the correct bolt on there. When top is off, it is open and interrupts connection to ground. However, the test by jumping pins ^^ to ground bypasses that. Said test checks control relay functionality directly, regardless of Cover Top status- but still depends on limit switches.

There are only 2 places for power to come into the rear window relay module; pins 6 & 8. I believe 8 is only a signal to tell the module that ignition is on. Actual power to motor and to limit switches come from pin 6, hence the circuit breaker.

Fortunately, I have not had the need nor chance [UNfortunately] to verify mechanical mounting and whether limit switches should be closed or open when glass is up/down, whether tailgate is closed or open, whether tailgate is locked/unlocked. I hope members with first-hand experience would chime in.

kushiel,
I think you're looking in the right direction. Figure out the limit switches, verify power to pins 6 & 8, make sure all is wired correctly to relay module & check again.

BTW, updated post above with location of rear window relay module.

Now... back to my roof rack install a la RBX & Redeth