The Stovebolt Site Forums The Shop Area The Electrical Bay problem lights

hi guys,
i have started to have a problem with the lights on my truck. my headlights have stopped working, the rear lights, front parking lights, turn signals and dash lights work but not the headlights, i also keep getting a fuse blow stopping all the above from working along with the horn! any ideas what might be the cause.
the wiring has been messed with and i have had to re-wire some of it. could it be the light switch or dimmer?

thanks

bill.

As one should know, if the fuse pops the circuit is drawing more currrent or amps than the fuse can provide. When does the fuse blow? When you turn the headlights on, blow the horn, apply brakes, etc. If it blows right away after doing one of the above, you might have a short in the wiring to that device. You also might be asking for too much from that one fuse. Maybe hooking the horn on another fuse will solve your problem. Better yet, add a horn and headlight relay if you don't already have them. Horns are known to be amp hungry.

Most often headlight problems are at the dimmer switch. It is in a horible invironment.

i am still investigating the fault, yesterday i rewired from termination block to termination block for the headlights and part of the loom going back to the switch, the cable going down to the dimmer is a bit of a mess but it is still intact with no copper showing. i am getting 11v at the termination blocks for the headlights when the switch is pulled out but not at all points. it looks like the previous owner installed a new switch, it looks new.
i am not sure when the fuse blows i need to look at that. the guy who had it before me has installed an assesory home made type of fuse block maybe thats causing the problem.
because it has had a V8 installed it has aftermarket temp and amp gauges, the amp gauge used to show normal (13v to 14v) but recently it is showing low in the red, when i apply the turn signal the amp needle moves up and down slightly as the bulb flashes on and off. its driving me nuts!

If your switch is designed as original you will only have voltage at one inner fender terminal post with the switch pulled out, the Headlight post.

with the switch out and you hit the dimmer switch you voltage will change between the headlight terminal and the hi beam.

Have you checked the ground wire for each headlight? Clean ground

Also try to test the headlights independently, Bring Voltage to the pigtail Hi and Lo lugs.
Once you verified your headlights work then you can continue troubleshooting
I have seen Orignal NOS Headlight switches are on EBay for around 80.00 U.S.