Rear tailgate doors

Hello all, so here's the story, when I try to defrost tailgate window nothing is happening :confused: I found long cable(4 pins)on the lef side of the truck that isn't even hookup and i have no idea where to look for female connector. Im pretty sure door's were exchanged for used ones in good condition therefore defrost isn't working. If u guys know where to look for it or at least rough location of it let me know, thanks :smile: Northern Sun

You will be needing the schematic for your year, the Haynes books are worthless in the schematics for Toyotas.
First check the indicator light does the DF (defogger) indicator light come on? For this to happen the rear window limit switch has to be closed, (window in closed position), the fuses all have to be good and relay circuit wiring all good, so if you have a light that comes on this is great news.
The limit switch just enables the relay circuit and indicator light, keeps the DF from heating when the window is inside the tailgate.
If there is a light but it doesn't come on then debugg the circuit first.
this will be tough to do without schematics.

If you have an indicator light then next would be to inspect the two wires that directly connect to the DF in the tail gate, these tend to get warm and over time become brittle and break, easy to find and repair though. Just open the tailgate, take a screwdriver and force on of the door latches into it's "closed" position,(just pull the door latch to "reset" the latch to it's open position) with one or both of the latches "closed" the widow can be rolled out of the door BECARFULL!!! the widow will need support or it will break its mounting so use a couple of milk crates with a blanket on them.
Roll the window half way out, that will put the wires right where you can see them, the breaks are usually near the strian releif point where they are tied to the window frame. One side of the DF should have continuity to ground the other should be connected to the relay.

SO if you have light and main feed wires look good and one side of the DF is grounded then start in the front there is a relay on most Toy DF circuits with the ignition to the "run" position (without starting, you will need to hear) turn the DF switch on and off you should hear the relay clicking, if not the relay most likely is bad if it clicks check the color of the heavy wire connected to the back, you’ll want the one that does not have 12v on it when the relay is removed. Take a test light with a very sharp probe and push through the insulation on that wire if you get 12v toggling with the switch then the relay is good.

Now find that same color wire in the wire harness going inside the tailgate, sometimes the color codes change on the way that’s why you should work from schematics. There is only be one wire from the junction/relay block to the DF the other side of the DF is connected to ground through the wire harness to the chassis ground point.
Get schematics, good luck.

WHEW! I need to get a life!

First check the indicator light does the DF (defogger) indicator light come on? For this to happen the rear window limit switch has to be closed, (window in closed position), the fuses all have to be good and relay circuit wiring all good, so if you have a light that comes on this is great news
yes it does come on, i mean indicator light for the df by the dash. I also checked fuses and then i found that 4pin disconnected cable on the left side of the inside of the truck.

So u saying that df power cable should or possibly has 2pin instead of 4pin? In that case, what 4pin cable is there for? :rolleyes: maybe for hooking up lights(trailer?), i'll make some pictures tomorrow,

P.S Im pretty sure i don't hear that click, ill have to double check on that, thanks for reply

i can hear that relay somewhere in the dash area as soon as i hit defrost button, so it got to be connectors as u sayin, will check them out this afternoon.

The 4 pin connector would be for an "option" that was not installed at the factory its cheaper to just install "one size fits all" harness than to have the vehicle at that stage of assembly start branching out to specialized sku's.
The DF is part of the rear harness and will be in a "bundle" of wires and go through multi pin connectors ~18 - 20 pins.
Open up the tailgate and start following the wires one of them will be grounded THROUGH the wire harness to the chassis ground point inside the the cargo area the other should have close to 12v.
Thes wires get brittle near the connection to the window and my bet it is there you will find your problem.
Good luck, I commend you for tackling this job it is by no means a small task.

there is no power coming to df :uhoh:, since whole door were changed whole bunch of cables were cut off and reconnected again, im putting my bet on that, its still too cold to lay under the truck :disappoin, ill keep u post it and others as soon as i made some progress in fixing that, thanks again, N.S

All the wiring is inside except for the section that goes to the tail gate. SO run a tempaory wire from behind the relay to the tailgate then under that mat on the tail gate then you have a defogger until its warm enough. Just tuck it under your floor mats.
On a 92 it is the green with WHITE stripe careful there is a green with BLACK stripe also.
Heck just connect it directly to the "push on" connector at the window youll want to ground the other connector back to the chassis ground not the tail gate not a good ground.

4Wheel after reading all the above I have to say...GREAT POST BUD!!!!

To Northern Sun......if you do happen to run a wire as 4Wheel says...be sure and run wire temporarly connected to defrost ribbon in such a manner that it is not accidently *snagged* and rip ribbon......running wire to side of floor or side of roof (I have no ideal which since you did not post year of your 4runner) and duct taping it along path to parting line (remember to give enough slack if closed at time) of tailgate/hatchwill cut down greatly the chance of a big oopsie or OH F*CENSORED* happening....maybe you fix it later or take it out in spring and reconnect next winter-this is very common to many of my temporary,jerry rigged repairs that I later and later and later say I will fix that later but it works for now so what the heck......(shut up (j/k) and stop laughing 4wheeler I know from reading your stuff that you do this alot too lol)

Anyways goodluck Northern Sun and again great post 4Wheeler

WHEW! I need to get a life!

LOL!!!!


Just a heads up bud....I noticed in post you said 92....I have a gas hawg , poor performing-great riding smooth handling 92 4X4 3.0 V6 A/T and was looking at replacing leaking muffler... a catback mandrel bent system is easy enough and nothing major cept the bucks (screw headers as the power gains wouldn't be much worth the effort of tightening headers and collectors bi-weekly not to mention cost again,since intake is a joke at best.The factory exhaust is 2 1/4" at manifolds to pipe to muffler which is choked a bit at flange and on exit pipe coming out muffler is 2" all the way back....Catbacks offer UP TO a 17% increase (yeah right on ours huh bud lol) just from cat all the way back.

Today I went down to a local muffler shop and got them to set me up with a 2 1/4" in and out piped 2 baffle (most stocks are 3 baffle) turbo style (shorter) muffler (oval generic*cheap*alluminized coating ),weld pipe to flange I cut for Cat. to muffler pipe (since old stock one is restricted here), bend me a new 2 1/4" exhaust pipe from muffler back and install it all......

Cost without making flange or supplying one and just doing it from original Cat pipe back:$128.00-*Muffler and pipes from end of pipe where muffler cut off all the way back with hanger and splice pipes (old muffler was 2 1/4" in x 2" out x 21 long x 7 round and offset) *

I went a bit extra and made own flange to bolt up to back of Cat. cost of welding pipe to flange was half of cost of 2 splice pipes and gave more flow.... my cost would have been around $138.00 with helped the owner install new front bumper and grill on shop truck with tweaked frame and paid $100.00 even

This is a choice I made.....since exhaust exit is in the middle and muffler is on its side when installed,I drilled a 1/64" *weep* hole at the bottom on exit side cover of muffler(drill hole back to front and ..not bottom upwards) so condensation would drain and prolong muffler life

You may opt to go with a Flowmaster or better even lol.....Mine is a slight louder than stock (still quite as hell in drive way) with a *distant/faint* rumble in exhaust but man oh man does it make a 100 dollars worth of difference when pulling a hill at 70MPH in overdrive and moving off the line a bit quicker...yeah it is pretty quite and a bit *throaty* at the same time.

Beware it sounds and feels good to step on it but gas seems to go a bit quicker as you tend to step on it and hold it down more...

Enjoying the ride....Grump

..be sure and run wire temporarly connected to defrost ribbon in such a manner that it is not accidently *snagged* and rip ribbon......

GOOD POINT There is a strain releif at the defogger connections use zip ties here to secure.

I have no ideal which since you did not post year of your 4runner
90 v6 a/t, i will be working on it ,and other stuff this friday, (found garage for few hours)so hopefully i will have that fixed :grinyes:

Oh CRAP! MAKE SURE there is enough wire to go the full distance the window moves or the window itself will tear off the connectors!!

then watch the wires as the window is rolled up so they don't catch anything.
Double check that ground if its not grounded, not gonna work.

4Wheel,

This thread is a year old but it is relavent to ME now because my defroster is on the fritz! I'm over here in Bend (not too far from PDX) and it's dang snowy! This is a 1995 4Runner SR5 V6 4WD. Best truck I've owned yet. They don't make 'em like they used to. You can't even get a manual tranny anymore right????

I've gotten as far as the following:

1. Defroster light comes on and fuse is not blown.
2. Fuse terminal and molex connector that connects to the rear defogger terminal (black wire) both read 12V when the window is fully extended.
3. The white w/ black striped wire is ground (since the other is 12v). I get no continuity to ground from that molex connector.

When I hook my ampmeter up (in series) to the gnd molex and the terminal on the window, I get 0 amps. When I bypass the gnd molex and go straight to chassis ground, I draw 6 amps....which is still a little low I think. The alligator clips I'm using are only 20 - 22 gauge wire, so that might account for something. Either way, it still doesn't look like the thing is melting much.

I haven't tried the tinfoil measuring on the window tapes yet. I will try that next. Any other thoughts?? Your help is appreciated.

Thanks,
Spindrift

I fixed my defrost few weeks ago; tailgate was replace by previous owned with no original harness; recheck ur wires or better harness. Harness tend to get corroded or worse brake its connector within harness itself, hope it helps, N.S

3. The white w/ black striped wire is ground (since the other is 12v). I get no continuity to ground from that molex connector.

When I hook my ampmeter up (in series) to the gnd molex and the terminal on the window, I get 0 amps. When I bypass the gnd molex and go straight to chassis ground, I draw 6 amps....which is still a little low I think. The alligator clips I'm using are only 20 - 22 gauge wire, so that might account for something. Either way, it still doesn't look like the thing is melting much.

I haven't tried the tinfoil measuring on the window tapes yet. I will try that next. Any other thoughts?? Your help is appreciated.
Spindrift

I think you have your problem in hand, it's your ground. Its the white with black stripe.
6 amps should give some heat, bottom line is that the ground terminal should be very close to 0v and the other should be very close to 12v, well there will be some normal wire IR drop.
Doing the tinfoil check will only help to find individual trace opens and if there is no ground they will all read 12v RELATIVE TO A GOOD GROUND.
You may want to just run a 10ga wire from the ground side of your defogger to a GOOD chassis ground NOT THE TAILGATE.

Hey what do your license plate lights look like are they working? or dim?
Or when you turn on the defogger do they change brightness? They require a grounded tailgate to work. Same with the back-up lights.
Good luck

it's your ground. Its the white with black stripe.

heh....that's funny, I just spend solid 6hr with my buddy, try to solve this freaking electrical problem with taillights(both), one pin from the harness gone on both sides, left harness useless - got one from 94' , that was shot too. I even repined some sh%t as well http://dayne.dobrynet.pl/forum/images/smiles/icon_menu.gif,
to fix tailight and defrost. Defrost had broken circut in two places, stop/sygnal - ground (bulb housing - no contact between bottom and top of it) http://dayne.dobrynet.pl/forum/images/smiles/icon_krzywy.gif
If i where U, I would check both connectors that sits directly on the window rail, they might look very good, but .... :icon16: that's it, get new ones, mines where http://dayne.dobrynet.pl/forum/images/smiles/icon_killer.gif, also check harness that sits in left rear bumper, (mine went missing, and rest of what's left endup in foam, probably quick fix & fake bumper) http://dayne.dobrynet.pl/forum/images/smiles/icon_hahaha.gif

U can do it http://dayne.dobrynet.pl/forum/images/smiles/icon_ok2.gif, its not that hard, lock ur tailgate and extend the window, that's it, hope it helps, later N.S

4wheel & Northern Sun,

I bypassed the whole shootin' match and ran a piece of 14ga straight from the battery to the terminals on the defroster (with my ampmeter in series). Still reads 6 amps so other than the broken ground wire, it seems to be drawing that as its max. BTW, this also draws 6 amps when the black molex connector is hooked up and I am manually grounding the other terminal to the chassis, so I think the + side connector and wire is good.

What I'm wondering is what does a new normal defogger window draw? Any of you care to measure yours for me? I'd be greatly appreciative! Should I be able to feel heat on the wires or is the heat so slight that we can't feel it with our hands????

4wheel, my license plate lights are fine (as well as my other electrical components). They don't dim when I turn the defogger on (mainly because its in an open state unless I rig it up to actually draw.

BTW, the resistance across the two terminals on my defogger window is 2 ohms.

Thanks,
Spindrift

i think there is a switch for it too; make sure u got right fuse while runing directly from the battery, voltage is rougly 10v as far as i remember, anything below no good. Electrical system is a joke, mine was all jumpy :mad: and by the way, u might not be able to fix ur defrost, i know for a fact that window rails on 89' and below are shot when it comes to defrost these days or 16yrs later, check the circuit of the window itself, N.S

The other lights will only be affected if it's a "global" ground issue with the entire tail gate, I looked at the schematics and you should have a good ground at the tail gate if the lights work.
6 amps should be about right I have never measured.
I will measure when I get around to repairing the open traces. The schematic for the defrogger is not complicated, just having one to follow is the secret to making this easy.
Goosd luck.