Headlight Meltdown . . .
 

I have been having major problems with the headlights of my '87 Mustang. At first it would start to get a little warm up where the switch is on the dash. Then it melted down the back of the switch where the plug goes. So I replaced the switch, and it happened again. So I made a bypass switch from a toggle switch(like the kind from switch panels) and the same thing would happen!!! She melted the electrical tape off and burnt up the connectors, so I replaced that again and checked over the wiring, but it still happens. Is there such a thing as some type of sensor some where in the dash that may have gone bad and caused this? Does anyone have any idea what may be causing all these problems? I thought that maybe I might have a short some where but wouldn't a fuse blow? I'm in desparate need of information, so I would greatly appreciate any theories or opinions.
Thanks alot!
Christina

if you use a bypass you are going to need a high amperage switch and a relay with at least 14 ga wire the headlights are using too much amperage for your switch and it gets hot and melts when using a relay it carries all the amps so the switch doesn't have to possibly the factory relay has gone bad and is allowing the switch to carry all the amperage i'm not sure where the relay is located if you have a chiltons or haynes manual you can chase the relay down on the wiring schematics.

You may have a bad connection ... bad connection equals resistance and resistance equals heat, especially in a low voltage high current system like a car. Check all the crimp on connections in that circuit and make sure they are tight ... also where you have mating pens or spade clips, make sure they mate together tightly also.

Christina, is your 87 a GT or LX? GTs have a known problem with fog lights and headlights being on at the same time. I rewired mine and it works great now. The problem is that they used too small a gauge wire for the headlights. Rewiring it with a bigger gauge wire will probably fix the problem if it isn't being caused by a poor connection as already mentioned.