PDA

View Full Version : overheating headlight switch and wires 1993 svt cobra mustang


roberto
07-20-2005, 10:55 PM
does anyone know the cause of this problem? fox body.
does anyone know the cure? i have changed the headlight connector. it has improved but when i put the fog lights on, the wires to the connector get noticeably warmer. the lights have flickered and gone off before i replaced the headlight switch. the hl switch is clean inside and the connectors to the multi-switch are like new. i have run the car with the fog lights on for only 15 min. after putting on the new hl connector. all the wires that i can see look good.
thanks.

RF Cobra
07-20-2005, 11:41 PM
On the fox body Tbirds the problems you describe were most commonly caused by the switch (the built in self resetting circuit breaker goes bad). Other possibilities are short in wiring and ground connection.

With the switch, low beams would work fine until the fog lights were turned on and then the lights would start cutting out.

Diagnosing and finding electrical problems can be very time consuming. Good Luck!

FCorkran
07-21-2005, 08:46 AM
I was just reading the other day that Ford undersized the foglight wiring on the Fox bodies (never had one with foglights). Now that the wires are 15-ish years old it's likely gotten worse. When the headlight switch circuit breaker in my '83 started cutting out after running the high beams for a while (and quickly got worse as the breaker failed) I installed a fused relay under the hood to power the high beams (100W Hellas). Not only did it take the load off the headlight switch since it only sees the relay coil current, the lights got quite a bit brighter because of the short run of 12 ga wire I used from the battery to the relay. The factorys always seem to use the minimum wire size for the current (weight), so the voltage drop tends to be high - especially when the wiring gets old and corroded. The upside is bulbs that last almost forever.


Put a relay up front to power the foglights and your problems should go away. Or you could pull them out and make the holes functional - brake duct openings! :D

RF Cobra
07-21-2005, 03:07 PM
That makes sense. I never experienced the problem myself but knew several others that did. Most everyone said the problem was made worse by the use of the fog lights so the fused relay is a good solution to the problem.

RF Cobra
07-23-2005, 12:32 AM
This looks like the answer to the problem.

http://www.corral.net/tech/maintenance/foglights.html