txclimber

Ok, I'm at my wits end and need a little help with my '86 4runner. Last week battery was dead, truck wouldn't start. Charged battery then started right up. Battery dead next morning. Started checking for battery drain by putting a meter between the neg terminal and cable and started pulling fuses. Found that I had a mystery drain of ~11a until I pulled the circuit breaker for the back window (part #82650-35010). Mystery drain isolated--sort of.

Now I notice that my rear window no longer rolls down with either the center console switch or the rear key slot. I had no window issues before.

Now I'm lost as to how to move forward. When the circuit breaker is in and I push the center console switch to try to open the window I do hear something clicking behind the panel near the seatbelt where the relay is.

How do I further isolate the problem? Is the circuit breaker bad? Can it be tested? How about the relay? Is there another relay in the tailgate? Can it be checked? How? I'm totally lost with this electrical stuff so please bear with me and be extra specific with any "how-to's". Thanks guys.

RAD4Runner

Your problem is a short somewhere, and probably not not the circuit breaker.
Inspect the the wire bundle running from that CB / Fuse block, along the door threshold, to the rear window control relay (module really), for shorts.

Still, check the rating for that CB. Should it trip at 11A?
Clicking of relay (inside the module) indicates that the circuit breaker has continuity, but double check, anyway. See rear window schematic somewhere in my build thread, check for 12V upstream side of it, and downstream side of it.

txclimber

I've looked it all over and can't see a short. All wires seem to be in tact. Where can I put a meter and what should it read? must i be pressing the window button to get voltage?

Terrys87

iTrader: (1)

RAD4Runner knows his electric and will be far more help to you then I could on this as electric is a weak area of mine. I do know from experience from behind the drivers side rear tire area up thru thru the body and into where the wiring goes into the tailgate, those wires can get really chaffed or scuffed up. That would be where I would have to start checking for bare wires. If you dont find it that way, RAD is one of the guys that can get you thru your electric issues.

RAD4Runner

Thanks, Terry!

So busy at office so no time to do illustration However, I suggest:
1) Inspect all the wire bundle running all the way to tail gate as Terry suggests for chaffing shorts.
2) Leave circuit breaker unplugged, if possible, until you find out what's drawing 11A. That's enough to melt / overheat a wire. You sure you measured the current right? Put Ammeter in series with the circuit breaker?

edeslaur

Rad4Runner just helped me on my window problem, which I literally solved today. There are more details here: https://www.yotatech.com/forums/f116/rear-window-goes-down-key-but-not-up-269310/
It calls out the chafing points I found.

This is also a very useful article: http://www.4crawler.com/4x4/CheapTri...arWindow.shtml

It is very unlikely the circuit breaker would cause a drain - it's either passing current or not and it would be exceedingly rare for it to short itself out without melting or starting a fire.

I'm betting the rear window motor is done/shorting internally, given the clicking of the relay when you try for down. the interesting article above includes some guidelines for testing the motor (weak, vs dead, but still helpful)

For the window down problem: Make sure your wiper is fully in the up (parked) position. I drove around for a week cussing Toyota rear window circuits because the window wouldn't go down until one day I realized the wiper wasn't fully seated in its parked position. I pushed it up gently with my finger, and the rear window was once again happy... LOL I doubt this is your issue, since you're getting clicking, but what the hey.

At the tailgate, and at the relay, you should get 12v at at all times (key, no key, etc.). All of these go into the relay as well in case you get that far.
1. the large blue wire with white stripe (power to motor for window down)
1a. the large blue wire with black stripe is window up power to the motor. Mine only had power when a switch was set to down (tailgate or center console)
2. the small blue/black wire (window down to tailgate switch)
3. the small blue/white wire (window up to tailgate switch)
4. the green/yellow wire (center console switch)
5. the red/yellow wire (center console switch
6. there may be others, I didn't check them all. I also didn't check what has voltage when switches are pressed.

If you use a test light on #s 2-5, it will actuate the window in different directions (see my link above for more details) since it's creating a ground. The lamp will not light except for #1 (will not cause window actuation). If yours goes down when you use a test lamp on the small blue/white, then there's an interlock which is keeping it from going down.

I'd check for power at the blue/white wires (big and little) in the jack storage bay - there's a connector in there. Check both side. If you have power there, next remove the tailgate harness cover (black plastic cover, 2 screws, which protects the harness where it goes into the tailgate) and check power there.

Check for power at the blue/white wires (big and little) at the tailgate switch. If you don't have power there, then there's a chafe somewhere else which is creating your drain.

If a check of the harness at the tailgate (driver's side, bottom of the gate) and in the jack area doesn't show any damage, it's time to open up the side panel and check out the relay.

txclimber

Update*********Problem Solved************

Edeslaur thanks for the extra detailed description and your guess was correct.

After many days of testing turned out that my rear window motor was fried causing the battery drain and preventing the window from working properly. It would have gone much faster and easier, but I only had a small window each morning to troubleshoot before it got WAY too hot in there.

Pulled my old window motor out and applied voltage and the thing would not turn. Got a replacement motor put it in and works like a charm, plus no more battery drain.

Thanks guys.

edeslaur

Great to hear, congrats!!