Fuse Box Corrosion and Fire

[Seanz0rz]

I discovered yesterday that the line to the fuse box under the hood corroded and caught fire:

with a flash to see the extent of damage:



without a flash to see the green color of the wire:


so what do you think happened? the only thing i can think of is at the end of September i drove through some salt water on my way off the beach at pismo. currently, the battery is disconnected, and it will remain like that except for moving the truck. i have no idea how long it has been like this, as i haven't opened that fuse block since last year.

thanks for any help you can offer. looks like it is time to replace/upgrade that wire!

[corax]

Corrosion build up increased resistance which generated heat and melted everything. I've seen this on alternator leads before. My guess is it's been corroding for awhile, not just since September. At least it probably didn't actually catch fire or it would have likely spread . . . still not good though

Now you have a good excuse to "up" the lead 1 gauge size and reduce the voltage drop to the rest of your system

[Seanz0rz]

yeah i instantly knew what had happened with the corrosion, i just cant figure out what would have corroded it so fast, the only thing i can think of is the salt water. im suspecting i might find problems elsewhere. i have replaced the wire to the starter, and the ground. the wire between the alt and the battery and the fuse box were left for another day, today looks like that day.

that wire appears to be either 6 or 8, so i will upgrade to 4 (which it definitely is not currently)

i actually have some left over from the vw rewire, but wont get a chance to work on it until friday or saturday, seeing as im spending roughly 55 hours a week at school or driving to/from.

[Bob98SR5]

Sean,

How much of the 4ga wire do you have? I have been wanting to upgrade the big 3 wires for some time. it would be great if you can document the length of the wire you will replace and the other two should you get to them.

[Seanz0rz]

IIRC i have 6 feet, which should be enough to replace what i need to replace. i already did the battery to starter, which i think was also 6 feet.

[slosurfer]

I really don't see how it would have been salt water getting up there, but who knows. It will be interesting to see what the whole wire looks like when you pull it.

Maybe there's a rip in the wire caseing down lower and it corroded all the way up the wire inside the caseing.

[Scuba]

Is that line easily reachable when you open the fuse box lid? I think that line is the problem to my electrical issue. But, I didn't know how to get to it.. so I haven't been able to check it.
When you pull it, would you mind measuring the length of the wire for me? I'd like to extend mine an inch or two..
Thanks Sean.

[4x4mike]

I blew the ABS fuse once and had to take the entire fuse box apart to replace it. Let me tell you it was a PITA but I'm glad I did it because the bottom of the box was full of moist sand. Sean I'm thinking that if you got water in there it stayed in there for a while and messed things up. I forget how long mine had been full of sand but I didn't have any corrosion. Might be worth it to take the box half way apart and peak inside.

[YotaFun]

The only time I have seen corrosion like that is here in the northeast.
Like Keith said Sean, that corrosion looks like it was a long time coming.

I need to do that big three mod myself, probably will when I tackle the 99+ interior upgrade.

Mike its interesting you say you had wet sand stuck in the bottom of your fuse block.
Makes me want to go check mine due to the number of times I have been through water and deep mud here...

[corax]

If you think there might be corrosion or salt in the fuse box, pull it out and rinse with rubbing alcohol to flush anything out. Make sure you let it drip dry and run a bit of air from a hair drier through it to thoroughly dry the insides. If there are any electronic bits in your fuse box alcohol won't hurt anything.