Headlight switch gone bad?

[bryan]

Headlights flashing in and out intermittently- switch VERY hot to the touch behind dash- is this typical of just a bad switch? I’ve replaced one myself before, just wanna make sure it’s not a bigger/wiring problem to watch out for

 

[tatersalad]

I've had them go out while driving and it was the foot switch for the high beam.. pretty common.

 

[bryan]

Would this explain the super hot switch? Assuming the dimmer is very easy to replace

 

[jckkys]

2 screws and a plug, but I agree the switch is a more likely suspect. The instrument illumination dimmer part usually goes first.

 

[bryan]

2 screws and a plug, but I agree the switch is a more likely suspect. The instrument illumination dimmer part usually goes first.

If you mean the turn-dial that dims the gauge cluster, it still functions normally

 

[Jfryjfry]

You can easily test the foot switch. There are three wires. One is the wire from the switch that will be hot when the lights are on. The other two are high and low and one or the other will be hot when the lights are on.

Or check for continuity on the switch. Unplug it. There will be continuity between two wires all of the time. If A is the hot in and B and C are the low and high, then you’ll have continuity with either AB or AC, alternating as you switch. You’ll never have continuity with BC

The switch will get warm at least but I can’t say if hot is too hot.
You could and even should get a headlight relay kit. It will reduce the load on the switch and give more juice to your lights, making them brighter. They are easy to install and the vendors have them I believe. Cheap, too.

 

[Pa PITT]

.. It's very common . shame they won't make us a brass dimmer switch very heavy duty.
I'll bet I've replace a dozen of them.. & MINE IS OUT AGAIN .
.. There is a relay wiring harness that helps a little but it's not a total cure.
. I bought one from a member here. & AFTER i SAW IT I thought that's not heavy duty enough . I wish I could fine it again . I'd buy another one bUT AFTER I got it home I'd take it & BUILD MYSELF A HEAVY DUTY ONE .. ONE WITH 10 OR 12 GAUGE WIRING. i'LL BET IT WOULD HELP.

 

[tatersalad]

Ditto on a relay kit.. much better system and a lot brighter lights.

 

[Broncobowsher]

These headlight switches (all Fords up through the 90s really) do not age well. Super common replacement item. When you unplug the switch take a second and check the plug for burned terminals. When it happens it is very apparent. Just a second to check, usually it is just the switch. I've only had a burned terminal once and I don't know how many switches I have replaced.