Blowing cluster fuse, with no cluster installed

[spotfitz]

'92 Pathfinder 2WD 4DR, no electric anything(windows,locks,mirrors,etc.)

I keep blowing the 10A fuse "meters" in ignition 2 bank(top right on fuse box). I have removed,unplugged the cluster and it will still pop(re: instrument voltage regulator). I have unhooked the alternator and it will still pop. I replaced all 3 Red fusible links with a Maxi fuse block(has nothing to do with this ploblem), but still have the main charging/power links(Black, Green) which isn't where my problem is. I have jumped these links with wire and it will still pop the fuse. I have checked the splice from the alternator power and it's still in great shape. I have replaced the ignition switch(electrical part). I have even tried putting a 15A and even a 20A in there. This was at a time in all disgust. 15A blew right away and 20A "slow burned" after some time driving. I've even joked about going even higher with the fuse just so I can find the problem. Whether that would be burning the harness or frying something else. Atleast I would no where to look!

I can pop this same fuse before ignition(just switching to "on"), while driving on smooth roads, while driving on rough roads(either/both, if the fuse hasn't popped after switching to "on"). It is very intermittent which is why I am having a hard time finding the problem. I have pulled the fuse box down and out to get to "junction C" to inspect the wires/junction with no signs of bad/corroded terminals, burnt or cut wire insulation(see 15A & 20A above). I have checked and switched the 3 relays at the fuse box. I have checked and switched the accessories and ignition relays under the hood.

My main problem with this blown fuse is not my fuel, temp and tach not working. It's I'm not charging! I'm on nothing but battery!

I think it's a short somewhere, but I'm out of ideas.

Sorry about the book, but I wanted to be as descriptive as possible. I know it's hard to diagnose an electrical problem via the Web.

BTW, where did the FSM's go? I can find a "ask me for FSM help" post, but I thought I had downloaded the '92 FSM from this site.

[Scottzilla]

I think the pre-94 FSMs were pulled due to copyright problems.

 

It sounds like you're just going to have to trace the length of the wire between the fuse box and the gauge cluster. There's probably a bad spot in the insulation or a pinched spot or something somewhere along that stretch of wire causing your problem. Look for places where it might be coming into contact with a metal chassis part.

 

The short is downstream of your fuse box so it shouldn't have anything to do with your alternator/charging. That is most likely a separate issue. You may want to pull the alternator and have it tested.

Edited April 7, 2009 by Scottzilla

[88pathoffroad]

Unplug the dimmer switch and see if it still does it.

[spotfitz]

It sounds like you're just going to have to trace the length of the wire between the fuse box and the gauge cluster. There's probably a bad spot in the insulation or a pinched spot or something somewhere along that stretch of wire causing your problem. Look for places where it might be coming into contact with a metal chassis part.

I was thinking the same thing and checked all that I could get to at the time. I guess I'll be pulling the dash to get to all the wires that I can't reach with the dash in. I may actually try to bypass the cluster power wire with another wire to see if it fixes my problem before I pull the dash.

The short is downstream of your fuse box so it shouldn't have anything to do with your alternator/charging. That is most likely a separate issue. You may want to pull the alternator and have it tested.

The first thing I did was have the alternator tested, which was fine. Eliminating all possibilites has been my way of tracking this problem down because of the randomness of it, which is why I disconnected the alternator and the cluster and still was blowing the same fuse. This leads me to believe it is an insulation problem on the cluster power wire. As stated, with this fuse blown I don't charge. This has me confused, unless it has to do with the charge light in the cluster being a part of the charge circuit. But with the fuse not blown and the cluster pulled I charge.

 

As for the dimmer switch being the problem. As stated before, I blow this same fuse with the whole cluster removed, which includes the dimmer switch.

But thanks for the suggestion.

Thanks for the replies and I'll post my fix if I don't park it on some railroad tracks first. LOL

It's sad. I've rewired my '74 260Z from the firewall forward with less trouble.

[Alkorahil]

It definately is not the cluster.

 

Somehow the ground on that circuit is now hot.

this can be caused by either loose connections or wire insulators rubbing over time and making a connection or someone installing something and not grounding everything properly.

 

The way to find out it to test the two prongs for the 10Ameter fuse.

 

Do this without goign through the multiple junction box.

One should be hot and one should be the ground. If the ground is hot, find out what wire color it is and then chase it to see where it is frayed/kinked/broken/fouled up. (Have fun with that!)

If you have a ground, then the junction box is messed up.

 

 

Whatever you do dont keep putting large fuses in, you can cause a fire, damage other electrical components and/or melt a wiring harness, that will be more expensive and more of a headache.

[spotfitz]

It definately is not the cluster.

Correct, since with the cluster out I still blow the fuse

Somehow the ground on that circuit is now hot.

this can be caused by either loose connections or wire insulators rubbing over time and making a connection or someone installing something and not grounding everything properly.

 

The way to find out it to test the two prongs for the 10Ameter fuse.

 

Do this without goign through the multiple junction box.

One should be hot and one should be the ground. If the ground is hot, find out what wire color it is and then chase it to see where it is frayed/kinked/broken/fouled up. (Have fun with that!)

If you have a ground, then the junction box is messed up.

I'm assuming the multiple junction box you refer to is "Junction C"

Whatever you do dont keep putting large fuses in, you can cause a fire, damage other electrical components and/or melt a wiring harness, that will be more expensive and more of a headache.

I know. It was a chance I took doing it.

The more I go over it in my head the more it makes sense that it is a frayed/kinked/broken/fouled up wire from the fuse box to the cluster. It has to be.

BTW, thanks for the PM help. [wink]

[Alkorahil]

I'm assuming the multiple junction box you refer to is "Junction C"

 

 

The one with the fuses behind the panel on the driver's side dash....

That is the 'super multiple junction'.

Or so Mr. Nissan calls it....

[spotfitz]

After some trouble shooting I have found that this "meters" fuse doesn't go directly to the cluster, but goes to 2 different relays under the hood. The wire clicks on the "Accessories" and "check relay" relays. So, it is safe to assume that this wire IS shorting out on something somewhere between the fuse box and these relays and that I can only find by removing the dash and stripping the harness down to nothing but wires and find the bad spot/spots.

I have thought of a work around to avoid doing that. Pull the wire out of the back of the fuse box and run a new wire to the relays after removing the other end of the bad wire. It will still work with the ignition switch and turn the relays on.

 

Error in my thinking?

I can't think of an easier way to fix this problem.

Anyone? Anything?

[88pathoffroad]

Does the fuse still blow with both of those relays unplugged?

[spotfitz]

Does the fuse still blow with both of those relays unplugged?

If I could get lucky enough for it to do what it did one day and just keep blowing the fuse when I switch ignition to "on" I could test that theory. With it being intermittent like it is, I have no way of testing it. I have tried switching relays around with the other relays in hope of it being a bad/worn relay with no such luck. Just yesterday I had a volt meter plugged into the back of the fuse box on the wire lead with the problem, just to see if there was a spike in the voltage before it blew and there wasn't one. I was driving for awhile like this on nice smooth roads and not turning either which way, then suddenly the fuse blew. I stopped and replaced the fuse with it running to check for a spike again and it blew the fuse instantly with no spike that I could register(damn digital greenlee volt meter). I put another fuse in and I've now logged 20 miles on that same fuse. I'll be running the test wire to bypass the "bad" wire today, just to make sure it isn't actually the ground wire side of the relays in this circuit. If all is well I'll hide this wire up underneath the dash and go from there. If all isn't well I'll track the ground wire to where it goes.

I was suppose to be receiving the wiring diagram from a site member here, but apparently they forgot. I should be able to finally get my FSM off the server where I previously worked today. Apparently the lucky bastards had Monday and Tuesday off this week.

This is sad. I always thought the idea for having a relay was to limit the power used to turn an item on through a switch while still providing all possible power to the component being turned on.

[spotfitz]

Well, after a week of not blowing the fuse I can state I found the problem and fixed it without running new wires.

I was going to jump one of the relays with a power wire and a fuse to see if without the blowing fuse connected it would still get power to the gauge cluster(find the relay that powers the cluster). Come to find out that not one single relay under the hood actually turns the cluster on. The wire coming from the blowing fuse actually does turn on 2 relays under the hood along with the cluster. I pulled every relay from under the hood and with the blowing fuse in place, I wasn't blowing the fuse and the cluster worked! I cleaned all the connections for all the relays and put everything back together and I haven't blown that fuse in a week.

Problem solved. To bad I didn't tink of this sooner.

I may be picking up an '87 4wd 5pd 2dr w/ 170k in acouple days. This one won't be left stock! I'm thinking SAS with 3" suspension and 3" body lifts w/ 33"!