The Stovebolt Site Forums The Shop Area The Electrical Bay Headlight issue (strange)

I turned on my headlights after I finished the tank install on my truck, and my pass. headlight was out. I checked it, it's connected. I had to disconnect the taillights to lift the bed, but there's only one way to connect them, and they're connected again. I did not mess with any wiring other that that, connected the existing sender wire and ground for the tank, so I didn't have to mess with any new wiring.

So, just before I decided to buy a new headlight, I tried my brights. Both headlights go out! Dims, driver's side works, brights neither. Tails, blinkers, and front markers/blinkers work, just the headlights don't.

I'm confused, please help!

thanks,
Tony

Tony,

The high beam and the low beam aren't on the same circuit. My wild guess is that the passenger side lamp is actually burned out and the high beams don't work because the dimmer switch is funked up...two different problems.

I think your truck has plugs/connectors for many of the circuits. Could one of those have been pulled loose in your wiring efforts.

The passenger side light, both high and low, series through the
drivers side light. Rattle the dimmer a bunch of times and see if the lights magically come on (hi).

Stuart

Thanks for the ideas and the info, Stuart. I did the whole rattle-shake to the dimmer, it worked last week and before flawlessly. I don't really know how old it is, but it looks fairly new. I'll double check the connections. I'm going to run thru the whole setup tomorrow, hopefully it's nothing major, but it still really weirds me out. I'm not sure if i can get myself to believe that the circuit for the brights would just go out like that. I know, they probably do it all the time, but it just doesn't seem like it's the answer.

Any other suggestions/ideas are welcome, too.
Thanks,
Tony

Weird problems often turn out to be a grounding problem of some sort.

I'd use a jumper between the negative lead on the battery and the ground pen on each headlight, maybe both at the same time, and see if that changes what is happening.

If that does make it work right you then would need to determine which ground is not working.

And maybe its something else entirely, but weird problems often seem to be ground problems so I'd check that first.

Thanks Steve. Another good idea for me to poke around with tomorrow.

Gotta say, I love that you guys are so willing to share ideas, I sometimes get stuck and overlook simple things, and it helps to be reminded. I once did a real stupid and sold a buddy my 80 pickup, couldn't get it to run right...

Turns out after I changed all the ignition components, messed with the carb adjustments, he got it and connected the BRAKE VACUUM HOSE and it ran awesome again... He wouldn't sell it back to me, you'd think I'd learn haha.

Troubleshooting electrical systems is so much easier if you have a multi-meter. It will tell you where you are getting power and where you're not, and if your ground is good or not. Even a cheap one will do the trick.