Headlight switch melted

[klawshot]

1999 Ford Ranger XLT 4x4 with 4.0 OHV and Automatic Transmission

Bought a cheap 1999 Ranger from a salvage auction earlier this year and discovered that the headlight switch is melted.

Not sure why this happened but I have replaced both the switch and the plug. The headlights still function as intended but the switch gets hot while in use (not just warm, but almost painful to touch hot) and have tried 2 switches with no luck. One switch was used and the other new if that matters at all.

Anyone know why this might happen and/or possible solutions to stop it from happening again?

 

[2011Supercab]

Are the headlights/bulbs stock?

Higher wattage lights can over heat the switch.

 

[klawshot]

Are the headlights/bulbs stock?

Higher wattage lights can over heat the switch.

As far as I know they are stock but since I just bought the truck I guess there is a chance that the previous owner swapped them.

 

[Curious Hound]

The older style light switches were known to eventually overheat. But it wasn’t something that happened in a short period of time. Something is causing high current there. Higher wattage bulbs could be an answer. Have any wiring modifications been done? For example, have any other lights been added to that circuit?

 

[klawshot]

The older style light switches were known to eventually overheat. But it wasn’t something that happened in a short period of time. Something is causing high current there. Higher wattage bulbs could be an answer. Have any wiring modifications been done? For example, have any other lights been added to that circuit?

No wiring modifications that I know about, and no additional lights

 

[Uncle Gump]

I've kinda attributed this to the heat generated from the panel dimmer resistor. Over time it deteriorates the plastic and also causes poor connections with added resistance that builds additional heat. Eventually... it just melts.

 

[klawshot]

I've kinda attributed this to the heat generated from the panel dimmer resistor. Over time it deteriorates the plastic and also causes poor connections with added resistance that builds additional heat. Eventually... it just melts.

Is there a way to fix that?

 

[superj]

are the head lights powered through a relay, or the power goes through that switch, like jeep light switches used to be?

if the power goes through that, i would make a relay set up to power the lights and use the wire from the switch to only activate/deactivate the relay power. then you won't have so much current in the switch

 

[SenorNoob]

Surely Ford didn't run all the power through that little switch. The older switches that were significantly larger had problems burning out that way. IF they did though their are premade relay kits for headlights. Just have to find one with your trucks' connectors.

 

[Ranger850]

Pretty sure this problem is common enough that it's been discussed here before. IIRC the fix is something like what @superj mentioned.

Multi purpose switch burnt up started smoking.

Ok so the other night Im headed home and i have a hard time seeing at night with my dim lights so I Went to use my Hi beams and I started to smell a really strong burning plastic type smell. I immediately turned off the lights and struggled home hoping not to get pulled over. well next day I got...

www.therangerstation.com

 

[klawshot]

are the head lights powered through a relay, or the power goes through that switch, like jeep light switches used to be?

if the power goes through that, i would make a relay set up to power the lights and use the wire from the switch to only activate/deactivate the relay power. then you won't have so much current in the switch

I believe the headlights are powered through a relay because while the switch was out the brights still worked

 

[klawshot]

Pretty sure this problem is common enough that it's been discussed here before. IIRC the fix is something like what @superj mentioned.

Multi purpose switch burnt up started smoking.

Ok so the other night Im headed home and i have a hard time seeing at night with my dim lights so I Went to use my Hi beams and I started to smell a really strong burning plastic type smell. I immediately turned off the lights and struggled home hoping not to get pulled over. well next day I got...

www.therangerstation.com

Unfortunately I have tried the fixes they mentioned in this thread and the switch still tries to melt

 

[bobbywalter]

99 truck?


check all related grounds and clean them up.

 

[klawshot]

99 truck?


check all related grounds and clean them up.

Thats a good idea, ill see how they look

 

[Curious Hound]

Check all connections in the headlight circuit, both positive and negative. Make sure they are clean and tight. Make sure the pgitails are plugged into the bulbs completely. It seems like something has changed and is causing too much current draw. I almost wonder if the new switch and pigtail you installed may have had an issue. Best thing, whether you find the root problem or not, is to make sure the headlights are on a relay so that the switch is only controlling power to the relay coil. But the factory wiring should not be overheating like that.