04 4Runner Electrical Nightmare!

[beantownguy2]

Greetings!

I set out today at 3pm to start installing emergency lights on my 04 4runner for the local fire department. I did not get far at all.

I started by wiring the switch first. I used the accessory fuse under the console in the fuse box as the source. Cleary, a terrible idea versus running a fresh wire from the battery. When I had my jeep years ago, that worked fine. 4runner - not so much! But, I learned from my mistake.

The switch powered up and stayed lit. But, when I went to turn the switch off I heard what sounded like a faint fizzle from what I thought was inside, and smelled a faint electrical smell.

Mechanically, it works fine. I am currently without stereo accessory power, tail lights, power windows, moonroof, and whatever else is on the circuit. All of the fuses and relays appear fine - at least the ones that I can see I guess. I checked all the ones under steering wheel, and under the hood.

Does anyone have any idea how I can approach fixing this? I had one of the local mechanics take a quick peak - he said it's probably a "fusible link" but he couldn't find where that was on the 4runner.

Any help would be great.

THANK YOU!

 

[drmorbius]

In the engine compartment fuse/relay box check the 140 amp alternator fuse. It feeds all the items you mentioned. Let us know what you find.

 

[beantownguy2]

That appears to be working as well.

I should probably add that my stereo (aftermarket) did it's "beep beep beep" noise when this happened. That's the noise it makes when it's turning off. If I had lost ALL the power to that area, it wouldn't have made the noise. It's just the accessory wire that lets it know the car is on.

Also, the daytime running lights don't work, nor does the backlight display under the stereo (the MPG display with the fan speed; the lights for the speedo, etc. work fine.)

Thanks for your reply - keep em coming, PLEASE! :bash:

 

[toto]

I'm not sure that the 4th Gen 4Runners have fusible links. From the few wiring documents I've downloaded from TIS, it looks like the battery is connected straight into the fuse box in the engine compartment; there's no mention of a fusible link. Fusible links are giant pieces of wire that act like big fuses, and they're usually located between the battery and the rest of the electrical distribution system. I've seen them on Toyota cars, but I haven't seen one on a truck yet.

Section 8 of the Owners Manual does an excellent job of describing which fuses do what, so that might be a place to start.

Here's the power flow chart from the Service Manual. It tells you basically the same thing as the Owners Manual, but adds a nice picture.

 

[drmorbius]

In the left dash junction box look at the 10 amp dome fuse. This also feeds the non working stuff.

 

[beantownguy2]

According to the diagrams... the problems appear to run on different circuits - the moonroof is on something separate from the daytime running lights which is separate from the windows. Unless I'm reading it wrong?

For example... the 7.5A ACC fuse in the driver's junction box says that it controls several things, including headlights, power windows, wireless door lock control, and interior lights. But, my wireless lock and interior lights work, where my power windows do not.

Could I have burned out a relay of some kind? How can you tell?

Its not possible I messed up the ECU (right????)

THANKS!

 

[drmorbius]

According to the diagrams... the problems appear to run on different circuits - the moonroof is on something separate from the daytime running lights which is separate from the windows. Unless I'm reading it wrong?

For example... the 7.5A ACC fuse in the driver's junction box says that it controls several things, including headlights, power windows, wireless door lock control, and interior lights. But, my wireless lock and interior lights work, where my power windows do not.

Could I have burned out a relay of some kind? How can you tell?

Its not possible I messed up the ECU (right????)

THANKS!

I doubt it. It's pretty well protected. I'm looking at the schematics too and there are several fuses that go to those components. That dome fuse has popped up in other similar problems. I still can't find the location of the fusible links but I will keep looking.

 

[beantownguy2]

Someone else had mentioned that there are no fusible links in the 4runner.

It's just so weird. I know I made a mistake by connecting the lights to the accessory fuse - but if there was a short, shouldn't it have shorted out that fuse? I don't understand how the short happened somewhere else!

It has to be a fuse of some kind right? I mean, I didn't melt an actual wire somewhere I hope. That would be a nightmare to find.

Is it possible that I messed up a relay? (How could I tell if I did?)

Oh brother.

 

[beantownguy2]

I just double checked... the 140A Alt fuse is good to go - as is the 10amp dome fuse. I swapped the tail relay and the power relay from the back of the driver side junction box and that didnt solve it, so the relays there are good. According the diagrams - one of these should be bad! lol So far, it all looks good

 

[beantownguy2]

Let's see... the tail lights operate on the TAIL Relay circuit... the accessories (stereo) run on the accessory circuit after the ignition switch. Two separate circuits, one PITA problem! gosh.

 

[drmorbius]

The way to go with this is to remain calm and not go off in all directions at once. When you checked the fuses did you use an ohmeter or did you just look at them?

 

[beantownguy2]

Sorry, I am calm - normally this wired.

My buddy used a test light. The 7.5A ACC and the 10A Tail were both dead. And, they are on separate circuits. Maybe its possible I blue both the 50A AM1 and the 50A J/B - but I highly doubt since certain things connected to the J/B are actually working.

Are there any in line fuses maybe?

 

[drmorbius]

Try the 50 amp AM1.

 

[Falls]

What type of lights were you wiring in ? ER lights I know , but strobe , leds , rotating ?

 

[beantownguy2]

50A AM1 is good to go


I was going to be wiring in LEDs, but I only got to the switch!

 

[drmorbius]

The only other thing I see is something called a shorting bar. It's also in the inside panel box. You might also look under the box for black spots. Meaning look at the bottom of the board the fuses plug into.

 

[beantownguy2]

Where can I find the shorting bar? Thanks again.

 

[drmorbius]

Sorry it,s called a short pin. It goes to a white wire and looks like it plugs in like a fuse. I think the bottom of this board is like a pc board and there may be an open trace.

 

[beantownguy2]

Here's the big update... the tail lights and the items that run on the "power 30A" circuit such as moon roof and windows are back up and running. The 50A one under the hood was blown, but I could swear it wasn't yesterday!! Humph.

All I have to worry about now are the accessory fuses and the other ones that run on the ignition switch.

Basically, it appears that the accessories that turn on with the ignition are not functioning. All of these fuses checked out (I triple checked early today.)

Is it possible I melted a wire or something?

The tail light circuit ("power") is what I originally tried this project on. When that didn't work, I tried the accessory circuit. So, I fried both circuits! Except the first one was just a matter of fixing the fuse - this one doesn't appear to be as easy.

Is there ANYTHING I can do other than unwrapping all the wires? That's going to be quite the nightmare.

 

[drmorbius]

Hello again! Glad you had some success. I still think that I would want to see the underside of the dash fuse board. From what has been said it sounds like the problem is located there. Let us know what fixes it in any case. I haven't looked at that fuse box so don't know if it's a PITA to look under there. Good luck!