Electrical gremlin

[pete the puma]

well -B- mine is not a wild guess but one from 20 years as an automotive electrician. whats your field of expertice? manual reading is great and a good start but i think fieldwork and experience also have merrit. even more so than manual reading to some folks.now you may correct me( which i`m sure you will the point of this forum is to help others not a match of wit and know all. the solutions i describe are things i`ve actually come across in the shop over the years not read about in a manual lastnight. good day sir. p.s.Izelos the fuse is in the engine compartment. good luck with your problem. i hope you find the answer.

 

[Beowulf]

p.s.Izelos the fuse is in the engine compartment. good luck with your problem. i hope you find the answer.

Pete,
There are several fuses in the engine compartment. Which fuse are you referring to?
-B-

 

[Beowulf]

Okay, went and checked voltage. I don't have a label for the fuses inside the cab but the one in the second spot down on the left (15A) and the one in the fourth spot down on the right (10A) do NOT have 12V in ANY key position. Otherwise everything checks out fine.

Do you have +12v at the glove box light? (Measure the voltage at the light socket. That should be easy to do but I haven't looked to be sure.)
Does your horn work? (Same fusible link as the DOME fuse)

It looks like everything that is NOT working is tied to your DOME fuse/circuit. We need to find out why there is no power to that circuit.

I don't have a diagram handy and my truck is not with me today. See if you can search here on 'Mud and find out the function of those 2 fuses that are not getting power. Maybe Pete knows.

-B-

 

[Beowulf]

Here is a diagram of the fuse locations for a 1997 US spec Land Cruiser. What vehicle do you have?

Let's be clear on a couple of things.
You say you don't have power to the TAIL and the A/C fuse, correct?
You say both fuses are good (continuity across the fuse) correct?

Check for power to the DOME fuse (see below) and check continuity across the fuse and let us know what you find.

-B-

 

[Izeloz]

This is a '92 U.S. spec FJ80. I checked and the fuse locations and purposes are identical. I DO have power and continuity to the dome fuse under the hood. I have power to the tail and a/c when those things are on (it was a little late last night when I checked them and it slipped my mind that they naturally wouldn't have power if they weren't on). I don't have any power to the glove box light. The ground is good but the power is non-existent. So essentially I have continuity and power to ALL my fuses but no power at the dome light, the glove box light, the stereo, or the vanity lights in the visors.

 

[Beowulf]

If you have power to the dome fuse and continuity across the fuse then that tells us that you are losing that power somewhere under the dash.

If the horn also works, that kinda confirms that your fusible links are OK. (Might be "weak" but we're not going there as of now.)

When you are measuring a fuse, there are 2 openings on the top where you can put your probe. Then you can put your meter to ohms and test continuity across the fuse. You can do this without removing the fuse. (Not trying to talk down to you but it is important that we can count on your reported results)

I will have to review the EWD and get back to you later... gotta work at my real job a least a few minutes today.


Another clarification Izeloz... to test for power at the glove box fuse you have to energize the tail relay by turning on the parking lights or the headlights. Did you do this before you tested for +12v at the glove box lamp? This is important and if you will follow along with me in your EWD you will see why.

-B-

 

[Izeloz]

No...I understand that you don't know my level of experience and have to have a baseline. I didn't remove any of the fuses to test them. I put the probes of the multi meter on top of each fuse on the test port and they all have continuity and 12 volts when they are supposed to (the resistance goes to 0 and the meter beeps when testing for continuity).

 

[Beowulf]

Need answers to these questions. 2nd request
Did you turn on the lights before you tested for +12v at the glove box lamp?
Does the horn work?

Can you get to the J3 connector? See diagram below for location. It feeds +12v from the DOME fuse to the other circuits that you have failing. If you can get to it we need to make sure each feed out of that connector is getting +12v. Look in your EWD to get the wire colors that go into this connector. That will make it easier for you to identify under the dash. I realize this is a PITA but that connector is important.

A +12v trouble-shooting lamp with a sharp probe would be the easiest to use for this.

-B-

 

[Izeloz]

Having problems finding the darned J3 connector. Still working on it.

 

[Lka1988]

Izeloz-

Here is a 91 dash, I've highlighted the J3 connector. The layout should be similar (if not identical) to your 92.

 

[Beowulf]

Thanks Lane. I am showing the TAIL fuse supplies +12v through the J4 connector directly to the glove box lamp. He says he has +12v at the DOME and TAIL fuse but he does not have +12v at the glove box lamp. J4 is the only thing in-between on my EWD.

What are you showing?

I am showing the DOME fuse supplies +12v through the J3 connector directly to the vanity lights in the sun visors. He says he has +12v at the DOME but the vanity lights do not work (they don't go through the ignition). J3 is the only thing in-between on my EWD.

What are you showing?

-B-

 

[Lka1988]

Grrr... This would be a lot easier if I had a physical EWD. Mine is an e-EWD

Is he testing the glovebox light with the running lights on?

 

[Beowulf]

Is he testing the glovebox light with the running lights on?

Yes, he is supposed to be testing the glovebox light with the running lights on.

-B-

 

[Lka1988]

Hmm... I'm showing that power to the glovebox light comes from the Tail fuse...

 

[Beowulf]

That is correct, the TAIL fuse.
-B-

 

[Lka1988]

Thanks Lane. I am showing the TAIL fuse supplies +12v through the J4 connector directly to the glove box lamp. He says he has +12v at the DOME and TAIL fuse but he does not have +12v at the glove box lamp. J4 is the only thing in-between on my EWD.

What are you showing?

I am showing the DOME fuse supplies +12v through the J3 connector directly to the vanity lights in the sun visors. He says he has +12v at the DOME but the vanity lights do not work (they don't go through the ignition). J3 is the only thing in-between on my EWD.

What are you showing?

-B-

I totally missed that edit...

 

[Lka1988]

Alright... I'm not showing the tail fuse going through any connector to the light... Just goes straight to it.

No vanity lights here, either...

 

[Izeloz]

Well...good news and bad news. The good news is that when I took my dash apart everything started working again. The bad news is that I have no idea why. I never did locate that J3 connector. I dug around in the harness and jiggled/tightened all the connections I could find in there. More bad news is that the power is still intermittent. The dome lights and door ajar lights and clock illumination will pulse dim and bright and the stereo will restart itself every time it dims. Gonna call it a night and look at it some more tomorrow. Never noticed it before, but the "key-in-ignition" buzzer appears to be part of the same circuit and will squeak like it's dying when the lights dim. Thanks for all the help, guys. If you're ever in my neck of the woods I owe you lunch.

 

[Lka1988]

The dome lights and door ajar lights and clock illumination will pulse dim and bright and the stereo will restart itself every time it dims.

Under what conditions? turn signal on? stereo thumpin'? hit a bump?

 

[Beowulf]

Need answers to these questions. 3rd request
Did you turn on the lights before you tested for +12v at the glove box lamp?
Does the horn work?
-B-