i know there are approximately 1.5 million threads on the rear window interlocks but i cant quite narrow down my answer. 1987 1st gen 4runner, rear wiper interlock is working, the hardtop bolt switch is working, the key works up and down, but the switch will only work in the down position. this leads me to believe that the switch is faulty but ive had several people (along with threads on this forum) claim that the switch is very rare to go bad. i know theres a relay of sorts in the driver side rear quarter outboard of the storage cubby, could a bad terminal be my culprit ? i have done my fair share of wiring up lights and stereos but i dont claim to be an electrician, fyi. one more tidbit, the little bulb inside the switch comes and goes, but i dont see why the bulb being bad would effect the performance of the switch itself. any pointers? -thanks

 

the relays for the rear window are actually in the rear passenger area, driver's side, next to the front seat-belt retractor, not the cargo storage area in the very back.

you can test the relay by grounding the pins without the switch. if the window moves up or down with grounding the correct pins, the relay is fine. then you'll need to determine if the switch is bad, or if the wiring is bad between the switch and the relay (that's my guess).

oh, and another good read on this particular subject (and many others): rad4runner's build thread, either here on yotatech or at t4r.

 

thanks for the tip. i also found some good troubleshooting on the relay at 4crawler. the only wiring that i know has been messed with is the oem stereo wiring, as with most 80s trucks it seems. like i said before, its odd to me that it works with the key and the switch, just not in the up position form the switch.. your speculation with not getting grounded to the relay makes sense to me.

 

4crawler is indeed an excellent source of information, too.

RAD points out a few of the factory wiring flaws in these toyotas, and how to fix the flaws. i've done a few in my 4runner (the headlight switch/relay issue, the starter key switch wiring/relay issue) to good effect, ie, these work flawlessly. i had to rewire the "up" wire from the rear window key-switch to the relay - it was cracked in several places, causing intermittent operation.

wally

 

Test the console switch. Those switches are often full of chaff cemented in with spilled soda pop.

I have seen several that would contact in one position, but not the other.

Often, repetative operation while running under hot water, followed by drying with compressed air will restore correct operation, but

sometimes the switch must be disassembled and the contacts burnished.

 

looks like i have a project for the day, thanks guys. going to pull the driver panel and inspect the relay visually, and try to take the switch apart and clean it with some electronics spay.