Need help trouble shooting rear defrost/wiper/window

Aquafbody

New member
I bought my 85 about two years ago and it has had the oddest problem with the rear end. So first off the previous owner decided that since the switch in the cab did not work that he should take the tailgate off and splice about 20' of wire that he would tuck into the rear bumper and touch the other ends directly to the battery to make it go up and down. I replaced the switch and motor but for some reason when the plug for the topper is plugged IN the window will NOT work but when I unplug it the window will work but nothing else does. Please advise:wtf:
 
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...when the plug for the topper is plugged IN the window will NOT work but when I unplug it the window will work but nothing else does. Please advise:wtf:

You mean Window works when it is NOT supposed to be connected?
Window motor works, correct? Why don't you test relay then restore wiring back to stock (check my schematic)?
 
You mean Window works when it is NOT supposed to be connected?
Window motor works, correct? Why don't you test relay then restore wiring back to stock (check my schematic)?

Correct when the roof off plug is UNplugged the window works but nothing else. When it is plugged IN nothing works at all.

I thought that I had reverted back to stock.
 
Last edited:
Correct when the roof off plug is UNplugged the window works but nothing else. When it is plugged IN nothing works at all.
I thought that I had reverted back to stock.

P.O. must have a bypass somewhere that you need to find.

... since the switch in the cab did not work ....
Meaning the tailgate switch works?
IF IT DOES, looks promising. If you want to restore to stock and make it more reliable, Remove P.O.'s bypass and test relay like I describe.
Inpect the wires inside the flex between body and tailgate.
 
P.O. must have a bypass somewhere that you need to find.

Inpect the wires inside the flex between body and tailgate.

Yes the switch on the console works but only when that plug is undone. I know about that switch under #14 bolt and it works too.


That's my thought, P.O. must have bypass. You remember about the 20" of wire thing he did. Your thread is helpfull with the schematics but I simply can not find the fault.

Do you think I have two seperate issues? Like perhaps a bypass on the window and perhaps a bad ground for the wiper/defrost. Do the wiper and defrost share a common ground or 12v circut?
 
This mod will allow one to roll rear window down from inside the rear deck (i.e., when camping in truck), without having to scramble over to front, put key in ignition in order to lower window from console switch.

Rear Window/Wiper Relay is behind panel near driver side seatbealt mechanism here:
rad4runner-albums-rear+window+control+mod-picture26042-rear-power-window-relay.jpg~original


Relevant wiring runs behind panel near left side of rollbar here:
rad4runner-albums-rear+window+control+mod-picture25617-20120819-013.jpg~original

Top Off Switch is also there.

Connector for Rear Window & Wiper Relay here:
rad4runner-albums-rear+window+control+mod-picture25616-20120819-009.jpg~original


Check against schematic here:

rad4runner-albums-rear+window+control+mod-picture25614-rear-window-control-system.jpg~original


Pin Numbering here:
rad4runner-albums-rear+window+control+mod-picture25615-electrical-piins.jpg~original


This mod will duplicate exactly what the key switch does:
Mod Schematic is here:
Rear_Window_Control_From_Rear_Seatsa_zps9a0957c2.jpg~original


Wire to pin 11 (light blue-white stripe) when connected to ground (via terminal 3 of top-off switch) will lower window.
Wire to pin 12 (lt blue-blk stripe) when connected to ground (via terminal 3 of top-off switch) will raise window.
(To test relay function, touching directly to chassis ground will work regardless of state of top off switch)

Wire a momentary SPDT with center-off switch (Up/Down) exactly same and in parallel with backdoor control switch (key switch),
I recommend to:
  • Locate switches so they are shielded from cargo by roll-bar, and
  • Add fail-safe feature by inserting SPST window lock switch between center terminal of Up/Down switch and terminal 3 of top off switch. (i.e., cargo un-intentionally presses against any of the switches.)
You can do this by carefully stripping off insulation on wires above, and tapping into them. As you can see in pic below, I have labeled Light blue wire with white stripe "DN". Near label, Lt Blue Wire with Black stripe had been stripped to accept tap for "UP" wire.
rad4runner-albums-rear+window+control+mod-picture25621-20120819-019.jpg~original


Good place to connect center terminal of SPDT (Up/Down) switch is on this crimp, just forward of top off switch:
rad4runner-albums-rear+window+control+mod-picture25619-20120819-014.jpg~original


Console switch Operation:
In same manner, touching wire going to pin 4 (Green with yel stripe) will lower window, and Pin5 to ground (Red yellow stripe) will raise it. This is where console switch connects. Connecting directly to ground bypasses console rear window lock and rear door lock detection switches.

According to your diagrams they do not.
 
The 20-foot wire is the bypass.

Possible reason why window does not work is one of the limit switches is saying, either:
(1) Wiper is not parked (wiper retract detect switch)
(2) Back window limit switch thinks window is at it's limit

When connector is plugged in, this signal reaches the relay so relay says do not move.
Try this:
Remove pin 13 from connector at relay, reconnect top connector plug, test if console switch works.
Re-install in 13, remove pin 2, test again.

That will identify which limit switch is telling relay NOT to move a thing.
 
The 20-foot wire is the bypass.

Possible reason why window does not work is one of the limit switches is saying, either:
(1) Wiper is not parked (wiper retract detect switch)
(2) Back window limit switch thinks window is at it's limit

When connector is plugged in, this signal reaches the relay so relay says do not move.
Try this:
Remove pin 13 from connector at relay, reconnect top connector plug, test if console switch works.
Re-install in 13, remove pin 2, test again.

That will identify which limit switch is telling relay NOT to move a thing.

Nice, Will do RAD Thanks. I'll let you know what happens.
 

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