I keep blowing my 15A dome fuse. Help

[Lanqe]

I already have the FSM offered to download in the sticky. But it does not include the correct fuse box in the dash and wiring diagrams. Does anybody have a 99-00 specific manual. Or even just the wiring diagram section?

I am having a problem, I keep blowing my 15A DOME fuse. I have narrowed it down to one plug on the back of the drivers side fuse panel. Any help?

 

[snivilous]

Someone help this poor mother****er, he's my buddy and we have had zero luck diagnosing the problem besides it being tied into the plug specified. If anyone has a 99-00 specific FSM let us know!

 

[LittleCaesar]

I have one but I wouldn't be able to put my hands on it until at earliest the weekend.

Has water ever gotten on or behind the panel?

 

[Lanqe]

I have one but I wouldn't be able to put my hands on it until at earliest the weekend.

Has water ever gotten on or behind the panel?

Who knows. I just bought it without knowing much about it and it is in pretty rough shape, so i wouldn't be surprised

 

[TheDurk]

Someone help this poor mother****er, he's my buddy and we have had zero luck diagnosing the problem besides it being tied into the plug specified. If anyone has a 99-00 specific FSM let us know!

Yeah, I have a paper '99 and '00 on disk. That is plug 1A and it distributes the DOME fuse power to interior light circuit. The full list of circuits fed by the DOME fuse is:
Auto Antenna (not on 1A)
Cigarette Lighter and Clock (not on 1A)
Combination Meter (not on 1A)
Headlight (w/ Daytime Running Light)(not on 1A)
Interior Light (fed by Pin 3 on Plug 1A)
Radio and Player (not on 1A)

The other circuits on 1A are the other roof based items like the sunroof that do not involve the Dome circuit.

The '00 EWD for the interior lights follows:

 

[TheDurk]

The first thing to do is confirm that the Pin 3 on Plug 1A Blue-yellow wire is showing a short to ground. If so, then first disconnect your front dome light Blue yellow wire and retest. Then do the same for vanity light and finally the lights by the sunroof control. Should be one of those three. If not, it's in that wire. Have you messed with any of those components lately?

Note: Rear dome is not on 1A.

 

[LittleCaesar]

IF it has an aftermarket radio in it I'd start there as long as there isn't any visible breaks or rust on the back of the panel.

Thanks to Durk for doing the work for me.

 

[TheDurk]

IF it has an aftermarket radio in it I'd start there as long as there isn't any visible breaks or rust on the back of the panel.

Thanks to Durk for doing the work for me.

Normally with DOME fuse, the first suspects are radio and cigarette lighter. However, neither of those are on the 1A plug.

Of course, someone could have tapped that L-Y wire for the aftermarket connection, or aftermarket anything. I think it's unlikely, as that wire goes from the aux fuse box up to the roof through the driver "A" column.

OP--I have a question:

How did you isolate the 1A plug? Because the DOME power comes in on the 1E plug, and pulling THAT should also have stopped the short on 1A from blowing the fuse. 1E is the one just below 1A.

 

[Magmotor]

How did you isolate the 1A plug? Because the DOME power comes in on the 1E plug, and pulling THAT should also have stopped the short on 1A from blowing the fuse. 1E is the one just below 1A.

Isn't the one he has circled the IE?? not the 1A (second one down) ??

 

[TheDurk]

Isn't the one he has circled the IE?? not the 1A (second one down) ??

Crap, you're right. Looked too quickly at the pic. So the first thing to do is pull 1A and rule that out. Then unplug radio and lighter in sequence. Or the reverse. My bad.

If those are good, then go pin-by-pin on 1E looking for the short. Come back, and I'll look up the pins.

 

[Lanqe]

Lots of good info and help already! so thank you guys so far.
It is indeed the E1 plug.

Crap, you're right. Looked too quickly at the pic. So the first thing to do is pull 1A and rule that out. Then unplug radio and lighter in sequence. Or the reverse. My bad.

If those are good, then go pin-by-pin on 1E looking for the short. Come back, and I'll look up the pins.

Ok so i have ground on 3 different wires. Going off the diagram posted by Magmotor, it would be wires 1, 4, and 5.

 

[Lanqe]

Alright guys. I figured out our culprit wire. It was number 4 on the plug, a blue wire with a yellow stripe. Which just so happens to be the stereo wire. I cut the wire at the plug and its holding a fuse now :hat: thanks for all the help everybody with the wiring diagrams and help. I was shooting into the dark without it. This place is awesome!

 

[LittleCaesar]

Also, in my experience, for the most part, a short in the wire when live, due mostly to broken wire(s), can be warm, even hot to the touch. And it may not be the exact wire, only on the same circuit.

Nice! Congrats!

 

[TheDurk]

Alright guys. I figured out our culprit wire. It was number 4 on the plug, a blue wire with a yellow stripe. Which just so happens to be the stereo wire. I cut the wire at the plug and its holding a fuse now :hat: thanks for all the help everybody with the wiring diagrams and help. I was shooting into the dark without it. This place is awesome!

In any case, I prefer to wire the full-time power on aftermarket stereo direct from the battery through an in-line fuse or aux. fuse box. Now you have to figure if it is the stereo or the wiring that is shorted. Good work!

 

[ColoRockyT4R]

Ok guys I must revive this thread. I have same exact issue and can’t believe there’s not more info on this so I want to try and get this fully hashed out! I have a 00’ 4Runner jumper cables crossed and have ran down the blowing 15A fuse to plug 1E on the driver j/b. Once I removed the blue / yellow wire the fuse no longer blows but STILL no power to any dome light, door chime, key light or stereo. OP says that blue/yellow wire is for stereo however nothing is getting power still and I see that dome light do also have blue/yellow wires going to them and it seems that everything going to the 15A dome fuse under the hood is all on that same wire anyway so how can I track this down?

 

[brillo_76]

From that junction. Where it no longer blows. Verify you dont have continuity to ground. Blowing fuses mostly happen for 2 reasons.

1] wire shorted to ground somewhere

2] drawing more current then the fuse allows.

Most likely you are going to need the Electrical wiring diagram for the dome circuit which is in post #5 of this thread.

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[negusm]

From that junction. Where it no longer blows. Verify you dont have continuity to ground. Blowing fuses mostly happen for 2 reasons.

1] wire shorted to ground somewhere

2] drawing more current then the fuse allows.

Most likely you are going to need the Electrical wiring diagram for the dome circuit which is in post #5 of this thread.

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Well it's really only #2. #1 is one cause for #2

 

[brillo_76]

Well it's really only #2. #1 is one cause for #2

Not really. You can pull 15 Amps on a 10amp fuse and it will burn open.

Or you can have a wire insulation rub off and ground to chassis [ vibration issue or movement of wires in the door jams or tailgate under those boot]. Wire insulation can wear through.

Can also happen when the wire holders get busted and cut off especially in the engine compartment from the engine to sides as the engine can vibrate and in time wear insulation off if not properly secured.

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[negusm]

Not really. You can pull 15 Amps on a 10amp fuse and it will burn open.

Or you can have a wire insulation rub off and ground to chassis [ vibration issue or movement of wires in the door jams or tailgate under those boot]. Wire insulation can wear through.

Can also happen when the wire holders get busted and cut off especially in the engine compartment from the engine to sides as the engine can vibrate and in time wear insulation off if not properly secured.

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Nope. You can ONLY burn a fuse by pulling too much current through it.

Wiring insulation that rubs off is causing a short and is pulling too much current through the fuse.

Your #1 is really the same as your #2 but #1 is just more detailed and just one reason of many.

Last Edit: I think what you meant to say is "#2 a device in the circuit drawing more current than the fuse allows.". Now you would have 2 separate reasons for the fuse melting. And I would have nothing to say...as yeah...those are the 2 most common scenarios.

-Mike

 

[brillo_76]

Nope. You can ONLY burn a fuse by pulling too much current through it.

Wiring insulation that rubs off is causing a short and is pulling too much current through the fuse.

Your #1 is really the same as your #2 but #1 is just more detailed and just one reason of many.

-Mike

Well I disagree two different conditions.

I have even seen fuse not burn and the wire have a dead short in it. This condition is extremely rare but it can happen. The fuse was good and the socket was good. Wire had continuity to ground.


I had this happen in a lawnmower and took me 6 hours to figure out the wire was bad. Replaced the wire. Never had another issue since. I also never replaced the original fuse. The wire wasnt broken from end point to endpoint [ including through the fuse ] even had continuity on the wire itself too.



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