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Hey guys,
I have a 66 that has a headlight issue. For awhile, everything was working just fine. Then, when I pull the light switch from the off position to the first "click" I get my running lights just fine (front, back and license plate). When I click to the second position for my headlights. My headlights are off, my front runners go off but my rear running lights stay on.
When strange things happen with auto wiring I check for bad grounds.
A little coroion can be troublesome.
A bad switch is on the list of things to check for. Do you have volt meter?
Try pull the switch all the way out and reach under the dash and wiggle the wires.
Let us know how these things turn out. There a lot more to check.
The front running lights go out when you turn the headlights on it's just a Ford thing for our 61 to 66 trucks.Get out out your test light and start checking for power starting at the head light plug.My guess would be a bad ground too.
My guess would be the switch. I rewired the lights on my 63 when I started having problems. I wired in a circuit breaker from the parts store, then later added relays to get higher voltage at the headlights for more illumination. Check for voltage at the headlights and work your way backwards. There is a ground at the front near the lights that, I believe is shared by the headlights and turn signal lights, so that may or may not be the issue since your running lights are working. Have you checked the fuses in the switch?
My guess would be the switch. I rewired the lights on my 63 when I started having problems. I wired in a circuit breaker from the parts store, then later added relays to get higher voltage at the headlights for more illumination. Check for voltage at the headlights and work your way backwards. There is a ground at the front near the lights that, I believe is shared by the headlights and turn signal lights, so that may or may not be the issue since your running lights are working. Have you checked the fuses in the switch?
Thanks for all the help guys!
I turned the lights on and jiggled as many wires as I could get my hands on. No luck.
There are fuses in the switch? I thought I read somewhere that the headlights don't have a fuse. Am I wrong?
Use a test light or a volt meter to check if power is getting to the 'H' terminal on the switch, the floor dimmer switch, and the headlights, with the switch on.
No fuse for the headlights.
Test lights are cheap and save alot of frustration. Fixing bad wiring is 90% patience, 25% understanding electricity, and 100% luck. (Math isn't required)
I agree with Mr.Fear. In addition to the above advice, I would also get a hold of the wiring diagram for your truck, or at least something close. Use that as a Map to trace from the battery to the load and find out where the power goes south. It will all make sense. B
Just to add to your initial post; when you pull your headlight switch to the second position; you state your front running lights go out and your rear tailight stay on; that's excatly the way its suppose to work; you didn't state where or not your license plate light stay's on or not but it should; I believe your dimmer switch is bad or the ground contact between the dimmer & floor board is not causing a good ground?
My dimmer is not working my bright lights; if I got my dimmer switch on brights the head lights go out until I switch back to regular lights.
Just a thought top your trouble shooting.
Just another though; during my rebuid; I had all my lights connect minus my dimmer switch and everything work except my headlights; but once I connect my dimmer than everything was back to normal operations.
Hey guys,
I checked the voltage going to the dimmer, it was fine at the switch. I then bypassed the switch (put in a short piece of wire to bridge the gap) and my lights came on! I plugged in the switch and jiggled the wires and the lights were sporatically on. Looks like the dimmer is the culprit!
Thanks so much for everyone's advice and guidance. Forums like this one make the internet worth all the spam email!