rockhound05

I just got a 93 LX coupe and was driving it the other night and it started smoking from the left side of the dash. Pulled it apart and the tan/white wire was burnt up coming from the fuse box. The brown wire on the dimmer was melted as well. I don't have any parking lights or instrument lights after this happened. As far as I can tell, the fuse was too big in the fuse box and let the wires get too hot. I actually cut the tan/white wire to prevent any fires under the dash until I can figure out what is going on. I must have a short somewhere to let it melt the wires. This was the first time that I drove the car at night as I just got it. I'm going to tear back into it this weekend and if I can't find something wrong, I'm going to wire up the parking lamps and instrument lamps on another switch with a relay and fuse. Anyone have any ideas whatmight have caused this?

rockhound05

Well, I got intothe dashwhen I got home from work. It had a melted wire from the fuse box (tan/white) up to the headlight switch. It also had a melted brown wire from the headlight switch to the dimmer. There wasn't any other wires that had any melted spots from the dimmer so I took my voltmeter and started doing some checking on the dimmer switch. Best that I can tell, the dimmer took a dump and the bigger fuse let the wires melt. I replaced the burnt wires and called a friend who has a bunch of mustang parts and he brought me a dimmer switch. It was working last night and I'll try it again tonight for a longer time. Maybe this fixed it. Is it a common problem for the dimmer to go out on the fox bodies?

mjr46

not really..never happened to me but they do fail..and what caused the wires to melt was most likely high resistance in a connection and or wire causing excessive current draw more so than the wire is rated for and uping the fuse allowed the excessive current draw to continue without popping a fuse until it was to late[:@]

rockhound05

Thanks for the info. While I was rewiring from the fuse box to the headlight switch, I looked at the fuses. There were several fuses that were larger than what they were supposed to be. I took out the larger fuses and put in the correct size for everything in the fuse box. Maybe this will prevent any future wire melting problems. If the fuse was the right size, it should have popped instead of melting the wires.

mjr46

in theroy it should of popped but it doesn't always work that way cause the high resistance in a connection often allows the heat build up in that spot and melts from there out....but by the time it's happened it always a mute point..cause the damage is done[:@]

ttocs

brown wire is the parking lights wire, I would look around the lights for any possible shorts.

I often wonder about people that will stick a bigger fuse in a spot that keeps blowing...

88white5.0

my harness did the same thing. i went through mine last week with a EVTM manual. good as new! i highly suggest you get a ford year specific electrical vacuum trouble shooting manual. you will be able to fix your problem.

rockhound05

Hopefully I got it fixed. I let it idle for about 20 minutes with the lights on last night before I put the dash back together and nothing felt hot. I replaced both the burnt white/tan and the burnt brown wires. I also replaced the dimmer switch which was giving funky ohm readings compared with the one I put in. I'll try and get one of the EVTM manuals. Sounds like it would be handy.

Thanks