Electrical meltdown - literally melting fuses! (1 Viewer)

[Southbound]

The past couple of days haven't been fun. First my truck would not move due to a clogged carb, then, once I got things going the truck started having a series of electrical problems. Fuses in the fuse box were literally melting, not just burning out. Parts of the fuse box itself melted. I really don't understand how that can happen. The fuses were the right amperage and I even tried using different fuses thinking the first ones were defective. I also don't understand why I would be losing fuses on multiple circuits. The fuses for the windshield washers, stop lights, and horn/hazards and the relay for the turn signals all blew at once. This happened when I turned on the headlights with the engine on. Ended up doing a cannonball run through sketchy ass Guatemala City in the dark last night with only intermittant lights trying to get to a safe haven in Antingua.

So I'm wondering if anyone knows A) why my fuses would melt instead of burn out and B)how on earth I can be having a problem with multiple circuits that as near as I can tell are completely seperate. Maybe I have a loose wire grounding across the fuse box. I am confused.

Thanks!

 

[Jan-78FJ40]

The past couple of days haven't been fun. First my truck would not move due to a clogged carb, then, once I got things going the truck started having a series of electrical problems. Fuses in the fuse box were literally melting, not just burning out. Parts of the fuse box itself melted. I really don't understand how that can happen. The fuses were the right amperage and I even tried using different fuses thinking the first ones were defective. I also don't understand why I would be losing fuses on multiple circuits. The fuses for the windshield washers, stop lights, and horn/hazards and the relay for the turn signals all blew at once. This happened when I turned on the headlights with the engine on. Ended up doing a cannonball run through sketchy ass Guatemala City in the dark last night with only intermittant lights trying to get to a safe haven in Antingua.

So I wondering if anyone knows A) why my fuses would melt instead of burn out and B)how on earth I can be having a problem with multiple circuits that as near as I can tell are completely seperate. Maybe I have a loose wire grounding across the fuse box. I am confused.

Thanks!

the circuits you mentioned are partially independent of the ignition, and partially not. that would suggest a general problem, like a major short somewere.
You need to start somewhere, and I would start at the batteries. Make sure the connections are good (at the battery poles and grounds), and the cables are not frayed.
Then move on from there. Monitor if there is a draw from the batteries with all circuits off.
check the connection at the starter.
you mentioned that this happend when you switched on the headlights. Check the connections and cables there.
Are the fuses melting as soon as you stick them in, or do you need to turn the ignition?
electric problems are no fun.
j

 

[cruiser_guy]

Do you have a wiring diagram and multi meter with you? I can scan and send a wiring diagram or you can get on on birfield.com

I'd look in the fuse box area for something across the fuses. There is obviously a major short somewhere.

Have the Guatemalan grease monkeys been under the hood? I try not to let them near my truck when I am there unless I'm standing over them. They like snipping "useless" wires!

 

[cruiser88]

pull your fuse box loose from the wall.im sure you will find a hot wire touching a ground wire directly.

 

[Southbound]

Thanks for the feedback and moral support. I do have a couple of good wiring diagrams. That's part of my confusion - the diagrams don't show any obvious points where all those circuits connect...except the fusebox. I'll take the whole thing apart tomorrow. I also have a multimeter. Honestly, I've never been so prepared for anything in my life, I've been able to deal with anything that's come along during this trip. Yesterday was ridiculous though, all my dreams of self sufficiency just went "poof" as system after system on Big Mama failed. I haven't let any Guatemalan mechanics touch anything electrical. Man I'll be happy if I can figure this out. Wish me luck!

 

[lovetoski]

Man I'll be happy if I can figure this out. Wish me luck!

Electricity is logical, and so are you. You'll figure it out!

Since stuff is blowing out so quickly, you might try something a little unusual...disconnect the battery. Get a 9V battery, figure a way to connect it to a 12V accessory plug. Plug the 9V battery into the cig lighter (you might need the ignition switch to be on). This should allow you to do some electrical testing w/out blowing fuses so quickly. It might not produce enough amps for testing all the circuts, but for sure will enable you to test some of them.

 

[Dynosoar]

Didn't you say in a previous post you had your 2nd battery ground out and cause a major short?https://forum.ih8mud.com/showthread.php?t=138639 post #1
I would start looking there. Check your voltage out of you alt at RPM to be sure your regulator is working as it should, thentrace all wires from the short back. It is a lot of work but now its a must do.

Dynosoar


P.S. I wish I was there to help you out.

 

[60wag]

I'd start with any non stock things that have been added to the electrical system.

 

[Southbound]

Thanks again for all the advice. Yes, I think my second battery disaster problably started the problem with a surge. It's disconnected now so I think the problem will be upstream. I found where someone tapped into the wires behind the fusebox and hope to locate the short there.

 

[cruiser_guy]

I found where someone tapped into the wires behind the fusebox and hope to locate the short there.

That is VERY likely the problem!! Anything connected to the constant hot wire from the battery can cause big problems if it's not properly fused but I think the problem is probably after fuses but at the fuse block because the power has to go through the fuse to melt it.

If you still have problems in a month or so I should be there!!

Antigua is a nice place to hang out even if it's a little more expensive than other areas in Guatemala. Take a walk up to the cross, sign up for Spanish lessons, visit the old buildings and convents, lots of things to do. The cross gives a great overlook of town and the Volcano beyond. You can drive to the overlook too but that's apparently not an option!

 

[cruiser88]

Thanks again for all the advice. Yes, I think my second battery disaster problably started the problem with a surge. It's disconnected now so I think the problem will be upstream. I found where someone tapped into the wires behind the fusebox and hope to locate the short there.

sort what i thought you may find

 

[Southbound]

Wow, well I think I've found and fixed the problem. One of the wires in the taillight circuit had overheated and fused with a variety of other wires all along the main wiring harness leading halfway into the dash. I had to take the whole dash apart to get to the wire and replace it but I've stopped melting fuses so I'm very happy. I realized the reason the fuses were melting and not blowing was because current wasn't even passing through the fuses - there was a short upstream that was causing the wires to overheat and thus melt the fuses. I'm thinking the bad wire must have initially melted when my battery shorted and I'm hoping that was a one time deal. This type of electrical fiasco was one of my worst nightmares traveling with my truck and but it turned out to be not so bad. Now to put my poor truck back together...

Yes, Antigua is a very pretty colonial town and while it is expensive for Guatemala it's still incredibly cheap compared to the US. I'm thinking about staying a couple of weeks and studying Spanish though I'd really like to get to Guatemala City to check out some diesel engines.

Thanks everyone.

 

[cruiser_guy]

Yes, Antigua is a very pretty colonial town and while it is expensive for Guatemala it's still incredibly cheap compared to the US. I'm thinking about staying a couple of weeks and studying Spanish though I'd really like to get to Guatemala City to check out some diesel engines.

Thanks everyone.

Stay for a few weeks and learn Spanish, it'll be beneficial, and I may be able to give you a hand finding engines! We are leaving here in one week to begin our drive down south. I bought the 3B for my FJ45LV last year in Guatemala City and I've been to several other places as well.

pm me your e-mail, I've PM you my e-mail.