Headlight switch gets warm
Thread Starter
Racer
Joined: Nov 2000
Posts: 290
Likes: 0
From: Omaha, NE
Headlight switch gets warm
I usually drive my 1979 Corvette in the daytime and until lately have not used my lights much. This weekend I was out “after dark” so had the lights on for an extended time. I accidentally touched the switch shaft and it was quite warm to the touch-not burning hot but very warm. It seems that when the panel lights are dimmed the shaft gets cooler-all of the lights work fine even though the rheostat feels a little “catchy” in places. I’ve never blown a fuse, the charging sytem seems normal and there are no other signs of malfunction. Is my light switch up for replacement or is there another solution? Thanks in advance for any ideas.
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Thread Starter
Racer
Joined: Nov 2000
Posts: 290
Likes: 0
From: Omaha, NE
Re: Headlight switch gets warm (Marv)
I posted this question on the NCRS board and got a two replies with possible explanations of dirt/corrosion. I also got an email from another member who said the light switch on his long gone 79 that he purchased new did the same thing and that he also discovered it by accident. The thoughts are that this is somewhat normal. So I'm bumping this to request that some of you folks with 78-82 sharks, and maybe other years as well, would run a test on your light switch when you're out driving around to check if this is a normal condition. Mine gets "quite warm" in about 10 minutes with the instument lights turned up to bright. Thanks in advance for any help with this quandary.
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Pro
Joined: Mar 2001
Posts: 500
Likes: 0
From: Michigan
Re: Headlight switch gets warm (Marv)
Mine is a little older, but same concept. The dimmer on the switch is like a big resistor/heatsink, it has a big spring within a ceramic casing that absorbs heat. That is how the dash lights dim. I think you are just feeling the heat that is absorbed which travels up the pull shaft. When I had mine apart last spring and grabbed onto the ceramic after running the headlights for about ten minutes, I burned my fingers!
Dwayne
[Modified by BigBlockVette, 3:25 PM 11/24/2001]
[Modified by BigBlockVette, 3:26 PM 11/24/2001]
Dwayne
[Modified by BigBlockVette, 3:25 PM 11/24/2001]
[Modified by BigBlockVette, 3:26 PM 11/24/2001]
Racer
Joined: Dec 1999
Posts: 485
Likes: 0
From: MESA, AZ, USA
Re: Headlight switch gets warm (Marv)
If the headlight switch is getting much warmer/hot than usual then it's time to check for a problem. Most likely problem is heavy load, or short through the dash light circuit, or a defective dash light dimming reostat (that "spring" wire that adjusts the current going to the dash lights). Either measure the current that is actually going to the dash lights and see if it's OK, or check out the reostat on the switch. Heat is a problem going somewhere to happen and needs to be resolved.
Andy
Andy
Melting Slicks
Joined: Apr 2000
Posts: 3,286
Likes: 8
From: San Jose California
Re: Headlight switch gets warm (Marv)
The light switch has a rheostat for the dash panel lights. If you have the dash lights at their brightest setting, the light switch should be only slightly warm. If you dim the dash lights for long distance night driving as I do, the switch will get quite warm. All the electricity that would have gone to the dash lights is now being bled off through the rheostat in the form of heat.
Chuck
Chuck
