I'm working on a buddy's 91 F150 and when you pull the switch on, the park lights/marker lights come on, but the headlights don't. The bulbs look ok, as do the wires. I haven't looked at the dimmer switch yet, but aside from that what could my problem be? Thanks for any help guys

 

The dimmer switch is where you want to look. It's problematic as it's in the dirty floor, and also it's an easy place to put a testlight or voltmeter.

It will have 3 wires. One hot wire coming from the headlight switch, and a low beam wire going out and a high beam wire going out. Pull the headlight switch, and the hot wire from the switch should have power. If it doesn't, you know the problem is up at the headlight switch most likely.

 

Hate to revive thsi thread, but this just happend to me on Thursday. I have a 1986 Bronco (fullsize) and I have the same issue (no headlights but have everything else). The only thing different is that the dimmer switch is no longer in the pathway...I took it out during my restoration and still have not put it back in. So do you think most likley mine is the headlight switch?

 

Your headlights will not work without the dimmer switch in place.

 

Sorry meantf high/low bem foot switch

 

Same thing, same reason they don't work.

 

Dang...its bean too long since I've looked down there. I'll check tomorrow what to see what my wiring looks like and run some tests to see what's up. Thanks franklin

 

Franklin...def on the dimmer switch...I had forgotten I stuffed it in the side panel and must be corroded. Time to get a new one. And screw that baby down. Thanks bud...easy fix!