More Than Warm Light Switch
Thread Starter
Instructor
Joined: Feb 2005
Posts: 199
Likes: 0
From: Fountain Co
More Than Warm Light Switch
Forum Pro's,
On my 78 SA while running either parking or driving lights the switch and outside molding around the switch gets extremly hot. Is the light switch fixing to short out or is this normal for it to be hot? Thanks for the help in advance.
On my 78 SA while running either parking or driving lights the switch and outside molding around the switch gets extremly hot. Is the light switch fixing to short out or is this normal for it to be hot? Thanks for the help in advance.
Pro
Joined: May 2003
Posts: 601
Likes: 0
From: Nottingham
Change it quick, but make sure you work out WHY it was getting hot in the first place. Has someone upgraded your headlights to H4 halogens without upgrading the wiring or installing relays? That was exactly what happened with my vette, and the light switch was gradually cooked over a period of months. It's a good idea to have a thorough check of all the headlight wiring up front under the nose, too. Mine was chafed and shorting to ground, another reason for the switch getting hot. Might need to do a bit of repair work on the loom. It's a bitch of a job but preferable to getting stranded with no lights, or melting your dash!
There's quite a few articles on the web about modifying your loom to use relays, and reducing the load placed on the switch in the factory setup..
Good luck!
There's quite a few articles on the web about modifying your loom to use relays, and reducing the load placed on the switch in the factory setup..
Good luck!
Drifting
Joined: Jan 2001
Posts: 1,347
Likes: 4
From: Slidell La
Fire
Many cars have caught fire from the headlight switch.. ref DOT safety info.
It should be warm on the ceramic heatsink for the variable resistor to dim the dash lights. BUt if it is as hot when you touch the dash. DON"T USE THE LIGHTS. The headlight current through that switch can result in an under dash fire and you will probably lose the car.
Replace the switch asap as others indicated.
99 nassau blue
It should be warm on the ceramic heatsink for the variable resistor to dim the dash lights. BUt if it is as hot when you touch the dash. DON"T USE THE LIGHTS. The headlight current through that switch can result in an under dash fire and you will probably lose the car.
Replace the switch asap as others indicated.
99 nassau blue
Racer
Joined: Nov 2000
Posts: 290
Likes: 0
From: Omaha, NE
I had a similar question/problem in the past but with the instrument lights. When they were bright the switch shaft/surround got uncomfortably hot and as I would dim the dash lighting it would cool down. I posted here and NCRS and got many responses but none worked. Had the console/gauge cluster out a couple of times, etc. I finally traced it down to NO ground connection at the rear light wire loom. That particular ground is bolted to the frame at the outside rear of the frame rail. The power antenna is also grounded there with the same bolt. On my early build 79 there wasn't even a hole in the frame but all of the grounds were bolted together and just hanging in the air so it was never grounded! After attaching it properly I had one COOL light switch. One would think the bad ground would be more closely associated with the interior lighting but ...... So you should make certain ALL your grounding points are good before you spend $. I had even bought a new switch but never installed it. If the switch feels "rough" when you dim the dash lights the rheostat may be toast. Good luck.
