Alternator fuse getting really hot

[GooeyGus]

So I noticed today that my alternator fuse is really hot. There is some melted plastic on the bolt from a previous alternator issue, and that plastic is beginning to get hot enough to smoke a little bit.

Resistance accross the fuse seems fine, maybe 1ohm. Connections seem tight but I only had about 5 minutes to check it out. It is the input side from the alternator that is getting hot. The fuse was replaced about a month ago.

Charging seems normal, my lights aren't super bright or anything.

The only changes I made to the car was adding an aftermarket speaker to the passenger side door, and also hooked up the passenger side dash speaker, which has never been connected since I've owned it.

The same night I added the speakers, my passenger side radiator fan stopped working. I used to use the AC button to turn it off and on, now it does nothing.

I really don't want a fire under the hood, but I just can't think of why one side of the fuse would be hot. I could really use some help!

 

[willydsm]

undo what you did, and or replace the entire line with the fuse in it, you may have a shorted out wire.

 

[GooeyGus]

I unplugged the deck (effectively reversing any changes I made) and took out all the relays that would har anything to do with the radiator fans. It still got pretty warm. I tested the cable and there are no shorts. From alternator to the other end of the wire there is only about 0.3ohm resistance, so the wire is good. I think my contacts on the alt fuse may just need a good cleaning. Although that doesn't explain my lack of radiator fans.

I'll try to clean up the fuse and report back.

 

[GooeyGus]

Fixed!

I took apart the alternator fuse and contacts, and it looks like the metal had formed an oxidation layer over the past 20 years. I measured voltage drop and it was almost 1v!!!! Lots of heat...

So I cleaned everything really well with a piece of purple scrubby pad stuff (you know the stuff I'm talking about...) and put it all back together. Now it's cool as a cucumber. Less than .05V drop across the fuse.

ALSO -- as a bonus, it made my fans start working again!!! I dont know how, but I spent all last night wiring up a switch to turn the fans on manually (normally I use the AC button). After I cleaned up the contacts, I decided the put the relays back in and see if it would work, and it did!

 

[LiquidX]

2 birds 1 stone, I like it! Have you checked any of your other fuses for the same corrossion?