JenniDawn

Hi everyone! I'm new here, so please excuse my ignorance if I've posted in the wrong area.. Also, if the question has already been answered, please kindly direct me there, since I've searched for hours before posting..

Lately my 95 4runner (6cyl, 3vze, 2wd) has been acting funny.. First, I noticed a surging idle (up and down about 500rpm every few seconds).. I attributed this to my small intermittent coolant leak.. But I also noticed my volts going up and down to the same tune as any load (like turn signals).. Soon, my Yota lost all electrical power while still driving..
Foolish me, since I'd never experienced this, thought maybe it was my very aged battery and replaced that to no avail (duh).. Against my very judgement, I also replaced my alternator since I was told it sounded like the volt mech inside the alternator was bad.
2 alternators and a new battery later, my son was driving the Yota and called me to tell me that he lost all electrical power but no engine problems... He pulled over to try to restart the car, but when he did, he was unable to start it back. I advised him to check & tighten all grounds visible, check battery terminals and I would be there soon. I borrowed my dad's truck to go "rescue" my son.. Tired and obviously brainless, I hooked the cables up backwards on the Yota (in my defense, the negative has a big red casing - no excuse, I know).. I told my son to lock it up, knowing I'd blown my 80a fuse.. I dropped my son off at home and picked up an 80a fuse ande headed to my Yota at midnight to replace my fuse..
Cold and tired, I dropped and lost the ground bolt attached to my 80a fuse, but then noticed that my 80a fuse AND the block it's attached to were melted. I got the new 80a fuse in, but there is nothing to reattach my ground wires to on the block. I called it a night and left my Yota figuring tomorrow I'd be more awake and be able to think clearer..
I can't find the block that the 80a fuse sits in at any auto parts store and can't afford to buy the whole fuse box from the dealer.
Can I just ensure that a nut and bolt are securely fastened to the ground side of my 80a fuse, and holding the 2 wires securely to it? Or is there an actual functioning purpose for the plastic block that the 80a fuse attaches to?
I didn't even get a chance to see if jumping the Yota off would help the original problem, but my negative terminal was a bit loose..

old87yota

Welcome, and thanks for describing your problem.

Hooking up the jumper cables backwards has come up here a number of times, so you are not alone.

Do you have a picture of the melted block?

The block, to my knowledge, is there to keep the 80 amp fuse in place and keep it insulated from other metal (to prevent shorts).

There may be someone here who has a spare they are willing to send you or there might be a salvage yard in your area that has the block you need.

Just so you know, there is no "ground" side of a fuse. Both sides are positive. The fuse is basically a special section of wiring that is supposed to melt and open first, before any of the other wiring does, and protects the rest of the wiring from catching fire if too much current goes through the wiring.

It is possible that there is more wiring damage beyond this 80 amp fuse. Some people get lucky and only have the 80 amp fuse blow, but others find more electrical issues after they fix the 80 amp fuse.

JenniDawn

Thanks for the reply Old87!
I'm attaching a picture, not great, but it shows the melted block. I wrapped electrical tape around, in hopes of diverting any problems that could arise.. The metal that the screw is attached to, is just the leg of the fuse (which was not originally visible, until it melted)...
I had to replace the nut and bolt that were on there originally because I dropped the bolt in the engine compartment (will never be found again) and the bolt was coated in melted plastic... I did get the Yota running again by doing what I originally said, and I'm absolutely shocked that my fusible link seems to be fine. The 2 white wires have some corrosion on them and they are brown/grey near the fuse. They had obviously been exposed to heat, but seem ok..

The original bolt on the 80a fuse, must have not been the original after all. It was a green bolt, so I assumed it was the "ground" side.. Thank you for correcting me, I have SO much to learn!

Wiring to one side of 80a fuse - melted block

ZARTT

I am taking parts from a 95 3VZE donor Runner to repair collision damage to my car.
If you still need a replacement fuse box assembly, I can remove the parts that you need and send them to you.
Let me know if this is what you want to do.

Art.

RAD4Runner

Welcome to the forum, JennieDawn! We're happy to help people who do their homework! And happier to keep them away from incompetent/dishonest mechs/shops who charge Yota brethren for their wild guesses.

Please clarify... The block that the ring terminal is screwed on to is the new 80A fuse?
What's the other block with the brass threads but nothing screwed into it?

Power Connections to battery on 1990-1995 are here: https://photos.app.goo.gl/B3gium1MYmw8jfGR8

JenniDawn

Art, that was completely unexpected from a complete stranger!! Thank you so very much for your kind offer!!
I would absolutely LOVE to buy and pay for shipping of this little piece that I can't find anywhere! Since it's intended to be removed from the fuse box, I've wondered if this isn't fairly common? I've blown a main fuse before in the past, but I've never melted one...

JenniDawn

Thank you RAD, for the warm welcome!! For the past year and a half, I was a mechanics helper.. I love the idea of it and I absolutely LOVE when I nail the problem right on.. Trouble is, it doesn't happen nearly enough. The mechanic that I was helping and learning from did a whole lot of guess work and throwing parts at cars, so I didn't learn enough from someone competent.. And I absolutely hate paying a mechanic to guess, since i, myself can do that much 😁 (certainly not bragging rights).. Thank you.. I've been reading from this forum for the last year now, and had every answer I needed the whole time. This was the first time I struggled to find an answer, so I finally joined.

The picture is horrible, I'm sorry!
The ring terminal that doesn't have anything screwed in, is the second half of the whole block that comes out. It looks as though it's for an additional fuse about the size of the 80a fuse. Possibly for an accessory that mine didn't come with? I'm attaching a picture that I found on this forum for a bit better understanding.
Your question does make me wonder though, if I could just use the other side, since it's not melted, for my 80a fuse?
My Yota is currently up and running, but my rigging of this fuse makes me nervous. And I do, definitely still have a surging idle and my volts visibly move when I roll my windows up or down... I'm losing power somewhere, but have a new battery and new alternator..

Yanked from this forum - my apologies , i don't have a name to give credit.

ZARTT

It is Sat night11:3- P.M. I am going to be working on repairing my Runner tomorrow if the rain quits.
I will remove the fuse box and its innards, and get them ready to ship.
I will let you know in this thread when I have it out and boxed.
Then we can PM email addresses for shipping costs and payment
I would ask for $35.00 + shipping to your zip code.
The part would be out of a 3VZE 1995 4Runner with a manual shift.
I would send the complete fuse box, along with all of its contents.
Is that satisfactory to you?

Art.

I regret to say that upon removing the fuse box from the donor, that the bottom of the whole assembly was burnt and melted
probably from a short circuit in a previous life. The wiring was all bare, and overheated. The piece that you need is unusuable.
I apologize for offering before I knew the whole story.
Art.

JenniDawn

Art,

Don't be sorry! Your offer was more than generous! I would have been happy to pay the asking price for it, but that's ok.
At least mine isn't the only one to have melted. Oddly enough though, only the small block is melted on mine, not the entire fuse box...
Thank you for taking the time to try, I very much appreciate the effort!
Any idea what the small removable block inside the fuse box, might be called? I've tried to search everything I could think of, to no avail..

user6137

Might not be part of your problem, but I recently had my engine die while driving down the highway (pretty scary). I tried to restart it, but it wouldn't start. The 15 amp EFI fuse was blown. It is located inside the fuse block under the hood. I replaced it, and the engine started right up. As for why it blew, I haven't been able to trace it down to a single cause. I searched for electrical shorts (didn't find any). I unplugged/replugged/cleaned a lot of the electrical connectors, and fixed the negative battery cable (that has been needing to be fixed for a long time). Haven't had it blow since.

RAD4Runner

What model-year, engine, tranny, trim?