zr222

newbie here with an electrical problem. A friend purchased a 95 4 runner and the rear defrosters do not work. I noticed that the rear passenger side glass has defrosters but the drivers side does not. This thing has defrosters on the back power glass also. All fuses are good. Before I tear into it and check the switch with a test light, has anyone else had a similar problem or know of a fix?? Any help would be greatly appreciated. Also the rear power window(tailgate) works from the back but not with the switch on the console. Thanks in advance.

colsoncj

On that it could be a few things... IIRC there should be a relay somewhere around the rear dr. corner that operates the defrost in the back glass, dunno bout the back side glass. When mine quit workin in my 87 (i know its different, but same theory still applies), i checked to make sure power was good at the relay, and was, then checked to see if the relay was operational, and it was, then checked all the grounds, which ended up being my problem... hope that at least gets ya started on the defrost.

Far as the rear window, could be a connection issue or switch issue... try takin the switch out, and jumpin the connectors on the swith connect to see if that will roll down the window.. if it does, switch needs a rebuild, if it doesnt, then its something else... however my money is on a faulty switch.

rezrunner92

The reason no defroster on the driver side is because the driver can't see out of that window anyway.

AW1090

is it a defroster in the rear quarter panel?....I thought that was an antenna. I don't think they came with defrosters in the rear quarter glass, but I may be wrong on that.

rezrunner92

My 1992 SR5 has defrost in the passengers side rear quarter glass. I thought they all had it but I don't have multiple runner experience.

Remove the console switch and spray it with electrical contact cleaner or quick start fluid. Try to spray inside as much as possible and then operate the switch back and forth a few times. Now set upside down to dry. Wait until the next day and re install and try again.

When I removed my switch I found a broken wire on the back.

RunnerUp

not sure if this helps, but ive heard that if you get tint removed and they cut a line it will cause the whole thing to stop working, might want to find out if it had been tinted

rezrunner92

That is true about the tint. I have personally seen this numerous times. Someone tints their windows in the driveway and while trimming cut the filament for the defroster. Then they bring it to me. Think of the filament as an extension cord. If you can find the break, (if that is the problem), you can fix it. They make repair kits. You may be able to find it at one of the mall type "parts" stores.

Astralplane

My problem was the wires were broken in half.
Pop off the carpet, unscrew the metal cover, and carefully/slowly pull of the plastic without tearing it.
The wires that goes up and down with window were broken from stress of the bracket it was attached to.
Little solder and tape and I was back in business.

zr222

wow thanks alot for all your help and suggestions. Ill try all these ideas out and see what happens.

GSGALLANT

Brace yourselves... this is a long post.

Mine wasn't working on my '93 4R. I took the rear door apart, and found that the power and ground wires were disconnected from the connectors on the glass (they're on the driver's side at the very bottom of the glass). I think there's supposed to be a small metal braket connected to the track at the bottom of the glass that holds the wires in place so that it doesn't rely on the connectors themselves holding tightly enough so that they don't pull loose.

My braket was rusted off, and the connectors had pulled loose. I just re-connected the wires and tie-wrapped them in position so they wouldn't come loose again.

Now, that was my experience, but I did troubleshoot down through your whole system, checking the easy things first.

Step 1: When you turn the defrost switch "on", does the indicator light on the switch come on? If not, then you have a problem in the low current circuit of the relay (or your indicator light bulb is burnt out). Check the 10A GUAGE fuse. If it's bad, replace it... if it's good, put it back. Pull the defroster switch out. There should be three wires connected to it. Ensure that you have approx 12V at the black with orange stripe and black with yellow stripe wires, regardless of switch position.

To check the switch itself, disconnect the blue with white stripe wire from it (while leaving the other two wires connected to the switch), turn the switch on, and check to see if you have approx 12V at the terminal that the blue with white stripe wire was connected to. If you do, the switch is fine. If you don't, and everything else in step 1 checked out OK, then the switch is bad.

Step 2: To check the rest of the low current circuit, with the rear window all the way up, check for continuity between the blue with white stripe wire (still disconnected from the switch) and ground. If you have no continuity, then suspect the rear window limit switch to be faulty (if could also be a broken wire or burnt out diode, but not as likely).

To bypass this part of the circuit to check the rest of it, go back to the switch. With the blue with white stripe wire disconnected, and the other two wires still connected, ground the terminal that the blue with white stripe wire was connected to, and turn on the switch. Does the indicator light come on? If so, you've isolated the problem to a small section (and likely the rear window limit switch is the problem.) if not, it could still be a burnt bulb so check for voltage at the defroster wires (note: a burnt bulb in the switch will not prevent the defroster itself from working. Check voltage difference between left side defroster wire and right side defroster wire on the rear glass to be sure of whether or not it's working.)

Step 3: If the low current circuit checked out OK, then check the high current circuit. Ensure all wires and fuse are re-connected from steps 1 and 2. Pull the 20A DEFOG fuse (driver's side kickpanel fusebox). then check for voltage at both sides of the fuse holder. There should be 0 volts with the defroster switch "off" on both sides of the holder, and approx 12 volts with the defroster switch "on" on only one side of the holder. If you have 0 volts on both sides with the switch "on", then your defroster relay is likely bad (it's located in the driver's side kickpanel.)

Step 4: If the voltage at the fuse checks out OK in step 3, then check for continuity between ground and the side of the fuse holder that didn't have 12 volts when the switch was "on". If it has no continuity to ground, then there is a break between your fuse and ground (either a broken wire going to the rear of the vehicle, or broken wire in your defroster wire on the rear glass, or your connectors on the bottom of the rear glass are disconnected like mine were).

Just something to get you started. Let me know if you need clarification on anything.

zr222

awesome , i printed out your long post. im sure it will help!! thanks!

GSGALLANT

Keep us posted on what you find. If nothing in my previous post helps you, let us know so that we can keep thinking about what the problem could be.

GSGALLANT

Any update on this issue, ZR222?

Denk

That is an antenna in the passenger rear quarter glass. I recently found the plug side of the wire, from off the glass, under the dash when I had the glove box out for some radio repair. I think the previous owner had it hooked up to a cell phone unit. I was surprised to see that it actually worked and was picking up good reception.

zr222

havent yet had the chance to work on it. its my brothers friend who just got the truck. Perhaps today since we are both off...