Melting Switches

Tiny
MYTRUSTYMERCURY
  • MEMBER
  • 1995 MERCURY SABLE
  • 113,000 MILES
My taillight and dash lights have not been working in my '95 Mercury Sable. So I checked all the fuses, and then I checked the switch. The carriage of the switch was melted. Cool. I replaced it. But after a few months the lights went out again. What's frying my switches?
Do you
have the same problem?
Yes
No
Saturday, January 22nd, 2011 AT 6:27 AM

1 Reply

Tiny
CARADIODOC
  • EXPERT
When the switch overheats due to cheap contacts, the terminals in the connector overheat too. That adds resistance to the circuit that promotes overheating the terminals on the new switch. That heat migrates into the switch contacts and accelerates the heat buildup there again and the new switch fails.

The proper repair is to replace the switch and to cut out all of the darkened, overheated terminals from the connector body. There will be at least two of them. New terminals can be installed and plugged in individually. About 4 inches of the wire should be cut off too and a new piece spliced in. The old overheated wire will be hardened and stiff, and solder won't stick to it very well.

Splice the new piece of wire and cover the joint with heat-shrink tubing, never electrical tape because it will become gooey and unravel in the summer heat. Be sure there are no sharp strands of wire sticking up that could poke through the heat-shrink tubing. You can use generic crimp-type terminals on the ends of the wires, but solder them too for a better connection. Be sure they fit tightly on the switch terminals. Squeeze them a little if you have to to be sure they're tight.

Caradiodoc
Was this
answer
helpful?
Yes
No
Sunday, January 23rd, 2011 AT 7:37 PM

Please login or register to post a reply.

Recommended Guides