melted fuse box

I've been a long time lurker, but now it is time to ask for some help.

Had a minor electrical fire under the hood yesterday. Melted the
fuse box on one end. I've searched the archives and didn't find any occurances like this.

Here's what happened...We (MN Trailriders were having a meeting and
annual vehicle tech inspection at ORO (Off Road Only) Saturday. ORO has had my XJ to tear apart the rear suspension and make templates for the kit this last week so I had the wife drop me off. They reported a dead
battery and having to charge it up prior ro test drives. I go to start it and yes the battery was dead. Put the charger on it and let it charge up a while. Started it up to move it outside and I notice the dome lights on. Tried to turn them off but they would not turn off from either the main light switch or the rear dome light switch. The voltage gage showed no charge with the engine running. Anyway, pulled it outside and it died going down the ramp. Checked the 60 amp fuse in the fuse box and found it was blown. Stuck the spare
fuse in and jump started it and it was showing a solid charge coming from the alternator. Decided to take it for a short freeway drive to charge up the battery, got about a mile down the road and hit a seam on the freway and saw the voltage guage drop to nuthin. Took the next exit and went a block & the engine died. Pulled over to the curb and that's when I saw the smoke coming from under the hood on the passenger side. Grabbed the fire extinguisher and opened the hood and saw the fuse box burning. Was able to blow out the flames of the burning plastic then disconnected the battery. Thank heavens for cell phones, I was able to call one of the club members and get a tow back to ORO and the meeting.

Has anyone experienced this before and can tell me what went wrong?
I have my suspicions but would like to hear it from the experts.

Obviously the fuse box will need to be replaced, how big a job is this going to be and will I need to salvage a wiring harness to go along with the fuse box. I am thinking that 93-95 XJ's fuse boxes will match what is in my 95.

BTW, I do have some pics, just no way to post them.

Thanks

Jerry H
MPLS, MN
95 XJ Sport, 4" AiROCK Prototype

I had one melt on me before, Its acually VERY common issue. Especially if you have a manual, when the master cylinder starts to leak it will drip clutch fluid on the fuse box causing it to begin to melt (shorts out). I replaced with a sealed-type fuse box on my 88

-Red

Actually this fuse box is under the hood up by the battery, this one is an automatic. I know where you are coming from, had an 85 with 5 spd that had the leaky clutch MC.

I've been looking at my FSM and the only things I can come up with as the cause of the meltdown is that I have a bad door switch which caused the battery to drain and then driving at highway speeds to charge up the battery the cable coming from the alternator thru the 60 amp fuse got hot and melted the fuse holder which when I hit that seam in the highway finally jolted the fuse enough to loose continuity and kill the charging circuit. After that it was just a matter of driving until the battery went dead. I think the dead battery and taking the full output of the alternator thru the fuse block for even a couple of minutes was too much.

Jerry H.
MPLS, MN
95 XJ Sport, AiROCK Prototype

You probably have an open MAJOR ground somewhere and the ckts were finding any route they could to complete hence the interior lights on.

You said you had a 85 with a 5sp and a melted fuse box at one time what did you do to fix the ploblem i have one on mine. Have to fight with fuses all the time thing of replaceing the under dash wiring with a pull from the yard.has any one replaced the wiring under the dash looks not to hard to do.

My solution on the 85 XJ was to trade it in on a new car, before I had any electrical problems. This was way before this kind of forum was available.

I hit the junkyard today and got a power distribution center unit from a 94 and a new vacum bottle for $20. The XJ is still over in St. Paul, will have to get a bud to trailer it home for me since I don't think the guys at Off Road Only will want to hang around after hours just so I can work on it in the evening.

Jerry H.

I had this EXACT problem on my 91, manual. Turned out the voltage regualtor, within the ECU was bad. There is an auxillary 60 amp charging circuit port in the underhood box, if you didn't completely combust it. I used this, eliminated the cooked wires to the primary, replaced the ecu with one from a salvage yard, and no further problems... Good luck!