New headlight switch HOT

[Mhfco6]

I replaced my headlight switch because the headlights were cycling on/off going down the road. The old switch did not rest on the dome light contact. The new switch rests on the dome light contact so the only way to turn it off is turn the switch clockwise a bit. This work but the ceramic wheel gets extremely hot. I’ll post up a couple pictures of the switches and my harness plug. Any help would be appreciated.

 

[Uncle Gump]

That "ceramic wheel" is actually a resister. A mechanically variable one... they do get hot anytime the head and/park lamps on. It sheds voltage to control the brightness of the dash lights. Where there is resistance there is heat. The wheel getting hot is normal.

It's been awhile since I have even used one of those switches but if memory still serves me correctly... turn the knob counter clockwise all the way... the dome lamp turns on. Rotate clockwise.... it turns the dome lamp off. Continue turning clockwise... it will dim the dash lights. Seems from your description... the switch is functioning correctly.

I also see your connector of burnt a bit.... probably the fault of your old headlamp switch. That burnt connector is not good... it also creates resistance... and heat. it will only get worse. I would at least try to clean the terminal and tighten it up to ensure it makes the best contact it can. But I personally would be keeping an eye out for a new connector.

 

[Curious Hound]

I think Rock Auto sells the connector with a short pigtail. I strongly recommend replacing it.

 

[Mhfco6]

That "ceramic wheel" is actually a resister. A mechanically variable one... they do get hot anytime the head and/park lamps on. It sheds voltage to control the brightness of the dash lights. Where there is resistance there is heat. The wheel getting hot is normal.

It's been awhile since I have even used one of those switches but if memory still serves me correctly... turn the knob counter clockwise all the way... the dome lamp turns on. Rotate clockwise.... it turns the dome lamp off. Continue turning clockwise... it will dim the dash lights. Seems from your description... the switch is functioning correctly.

I also see your connector of burnt a bit.... probably the fault of your old headlamp switch. That burnt connector is not good... it also creates resistance... and heat. it will only get worse. I would at least try to clean the terminal and tighten it up to ensure it makes the best contact it can. But I personally would be keeping an eye out for a new connector.

The switch is operating properly then, thanks! Old one must have been off a bit.

 

[Mhfco6]

I think Rock Auto sells the connector with a short pigtail. I strongly recommend replacing it.

Got it, I will get one ordered up. I did not notice the lights cycling on and off with the new switch, but that ceramic wheel was so hot I couldn’t touch it. Thanks guys!

 

[Curious Hound]

I don’t normally touch that. So I don’t know how hot it should or should not be. It only comes into play when panel lights are on and then, the brighter you set the lights, the less warm it will get because you are using less resistance.