Melting Fuses

[87CherokeeChief]

Over the summer i had been using my heater very little since i live in sacramento but on a trip up the north coast i had been using it and noticed the blower stopped working and saw the fuse was melted. was able to clean it out and get a new one in, thought nothing of it. fast forward to now, i had been driving most of the day and night with the heater on full trying to keep my windows from fogging. it shut off and the fuse was melted. any ideas on why? i dont believe the fuse is blowing out, just melting. and it is only one fuse, the blower. it is an 87 4.0 with a 5spd


Brett

[Matthew Currie]

It sounds like a steady overcurrent situation rather than a bad short. Stiff bearings on the blower can do that, and so can a burned out winding that has developed from overheating because of stiff bearings. There's no easy way to lube them, so you might end up needing a new motor. It's easy to remove, so I think the first thing to do is to pull it out and see if it's turning freely. Try to do it soon or you'll also burn out the blower resistors (that control low speeds).

[jerrywagner]

check with the Jeep Recyclers in Rancho Cordova for a replacement blower

[langer1]

It could be the motor and also the fuse holder has lost spring tension, that will cause a fuse to melt even if your blower is good.

[scoobyxj]

X2 I find this a lot in cheep aftermarket light wiring kits.

[Benzilla]

A bad relay could also be the problem...

[langer1]

A bad relay could also be the problem...
There is no relay in the heater system.

[87CherokeeChief]

alright i will check the bearings on the blower. i have an 85 xj also for parts, should the blower be the same?

[old_man]

Define fuse is melting vs. fuse is blowing???

Is the metal link open?

The plastic can get eaten by leaking brake fluid from the clutch MC.

[XJ Eric]

I've been running into that on both of my trucks. The blazer and cherokee are both melting (versus blowing) fuses. I think it because of the cheap wiring kit.
I can't figure out how to fix it. I don't want to put in a bigger fuse,, but I don't know enough about electricity to mess with it much

[dangerranger]

i had problems w/ a few fuses on my 90 xj, the radio and the blower. the fuses were melting, but not blowing. not comepletly melted, just warped some. new ones didnt seem to stay in right, i think they were arcing. figured there was something worn in the fuse holder. found if i drop a drip of solder one one side of a blade, they fit snugly and i have had no prblems. maybe not the most kosher, but it works

[87CherokeeChief]

Define fuse is melting vs. fuse is blowing???

Is the metal link open?

The plastic can get eaten by leaking brake fluid from the clutch MC.

Eventually it will blow...just one fuse though. and i mean melting from something like heat. ill look down there and it wont look like a fuse just a mass of melted plastic that i remove with a knife and pliers. i dont think it is fluid. however today i was driving in the rain and i felt water get sprayed onto my leg, so there is a hole in the firewall that water is gettin through.

[gjxj]

It has to be a problem with the fuse holder IMO. It should not get hot even if run close to the fuse rating. I'd probably just bypass the holder, run an inline fuse.

(assuming you are running the correct size fuse that is..)

[WB9YZU]

When I first saw this post, I thought "Hmmm, sounds like another 5spd XJ with a leaking clutch cylinder".

Clutch (brake) fluid does wonders for a perfectly working fuse block.