Headlamp switches - troublesome?

[Pinger]

As per title - are they known to go bad?
Driving in rain yesterday with the dipped beams on I noticed the switch warm to the touch. Kinda odd as I recently did the 4Hi mod and used relays so the load on the switch should be much reduced. Heating was on (low temp) and through the demister and foot vents so nowhere near the vent next to the switch.
An additional 'problem' I have is erratic dome light override switching.
Should I go straight to replacing the switch or do a bit of digging eg, measuring voltage drop over the switch and/or checking for problems in the other circuits fed by the switch? All lights are working and look as bright as expected.

 

[wirlybird]

I've never checked the switch on my 97 Tahoe for temp but also never had an issue with it. I think I did replace it when I did some lighting upgrades to the dash though.
It was one of those replace while you have it out deals.
The dome light override switch/button is fussy on both of my 97's. Have to push it a few times for it to stay.

One thing to look at maybe is where is the dash dimmer set? Maybe this is contributing to the warm feeling?

 

[618 Syndicate]

Checking stuff is free.

 

[Pinger]

One thing to look at maybe is where is the dash dimmer set? Maybe this is contributing to the warm feeling?

Good point as it creates heat when turned low - yes?
I have it set very low - I have white dials (not my choice - it was a conversion for the numerals to read mph instead of km/h) and they hardly need lit. Current preferred setting is the needles and not much else visible in the dark.

 

[someotherguy]

Dash light dimmer is a variable resistor so yes, the dimmer you set the illumination, the hotter it can get. It's noticeable.. also there's a small bulb that illuminates the switch itself (1995-up) so that will generate a little bit of heat on its own.

These switches aren't super high quality or anything. I've replaced more than a few 1995-up headlight switches, seems like more than I've replaced the 1988-1994 style. In fact the first one I recall doing was back in 2003 when I bought my 1996 C3500 out of town and drove it home at night using only the DRL's (amazing they still worked) and left a turn signal on to mark the rear of the truck, because the headlight switch had croaked.. and the hazard button was broken, as is also typical!

Oh and yeah, the dome override can tend to be flaky. You can take the switch apart if you're careful, and squirt some DeOxit in there, and work the switch on/off a few times to try cleaning it up. Pay attention as you disassemble as there's a little spring rod that the dome override button rides on, it's not tricky or anything but it helps if you give it a good look first.

Richard

 

[df2x4]

You probably already know this but I'll mention it just in case. Regarding the dome override, if your interior lights are already on when you hit the switch then you'll need to wait for them to go off before the override takes effect.

That said, if you're having a different problem with it then I'd say your suspicion of the switch is probably valid. I had to replace the one in my Suburban for similar issues. From what I've read they're a pretty common failure point.

 

[thegawd]

I would say yes, they do go bad. that dome override and dimmer function never worked on my burb. I didnt even know those were functions lol, I read it in the owners manual trying to figure out what the button actually did.

Something was also screwed on the Sierras light switch, I dont think the dimmer worked.

the burb got a new switch, the Sierra got a junkyard switch and I think I have 1 extra.

 

[thegawd]

I also seem to recall someone in the passed who also complained about the switch being hot. when he pulled the dash he found the heater duct above had fallen out of position and was blowing right on the switch.

 

[Pinger]

You probably already know this but I'll mention it just in case. Regarding the dome override, if your interior lights are already on when you hit the switch then you'll need to wait for them to go off before the override takes effect.

I'd noticed it - but not got on top of it. It doesn't bother me and now that winter is near I'm as well leave them (dome lights) on.

I also seem to recall someone in the passed who also complained about the switch being hot. when he pulled the dash he found the heater duct above had fallen out of position and was blowing right on the switch.

My smart used to direct heat to the stalk light switch - wise to that one!

Checking stuff is free.

So is a soaking from the rain! Pissing down here all day but you're right, checking is free. And will proceed with.....

Dash light dimmer is a variable resistor so yes, the dimmer you set the illumination, the hotter it can get.

..... the above.
Chances are it just the dimmer set really low. I can turn it up and dim the lights on the other dimmer. That I haven't noticed it before with the sidelights (I run with them on in daylight) might point to the dipped/main beam contacts being at fault - or my relays or wiring.
Things to check before I throw a new switch at it. I will get a new switch if the headlamp contacts are flaky. Losing the lights on an unlit road in the dark is a risk too far.

 

[618 Syndicate]

So is a soaking from the rain! Pissing down here all day but you're right, checking is free. And will proceed with.....

Thought you Scots called that liquid sunshine?