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

My hi beam headlights go on and off when the truck is ruining can't make it duplicate in the garage when the truck isn't running Is there a breaker or relay on the headlights that might be malfunctioning?

Bad grounds are always an issue. Make sure you have a good ground wire from your head light buckets to the grounded frame. Do not trust fasteners for your grounds. Otherwise, the hot wire from your lights to your dimmer switch.

does it happen only when you are driving? or when it is simply running (stationary or moving) It could be a short that only occurs when you hit a bump or something, like a wire getting rubbed through.

Just an idea

Some of the light switches have breakers on the back of them. If you are running Halegens it might be too much draw for it. If thats the case relays in the system help a lot.

WRENCH BENDER you might have it. The engine has to be running/ I did install new halogens last year.

I'm under the impression that a fuse or breaker's job is to interrupt current in a either a shorted condition or excessive current load by blowing or opening. Do they not have to be replaced (fuse) or reset (breaker) to restore power to the circuit?

A thermal breaker, which is a simple bi-metal contact will cool and self-reset. I believe this is what's on the back of some of the headlight switches.

Stuart

The AD headlight switch thermal breaker will chatter or buzz with a dead short and the bi metal strip gets really hot.

I have a new switch installed last year.

the switch overload circuit isn't rated high enough for the halogens, do the relay thing - proof would be to put original type bulbs back and watch the problem go away

Bill

Gazim,

I think I found my problem,you may try it also and see if it helps you. I ran a ground wire from the rear bumper to the bolt that holds the chain for the tailgate( stepside) clamped it on with vise grips, I now have headlights that stay on, I actually sat and watched them for 15 m inutes and they never went out. before within two minutes of turning them on they would be blinking off. I now have to make it permanent. Give it a try and see if it helps.

I kinda doubt it would help me. I have LED tail lights and led's in the box roll also and I grounded them well BUT I do have to do somthing so will try anything. Thanks.

Thanks Bill, You usually have good answers. I am trying to figure out if I have ever driven the truck at night since I installed the bulbs. Do Halogens use that much more juice?? How come it won't do it unless the motor is running?

maybe vibration of an oxidized connection? maybe even a poor connection at the headlight buckets, like the socket not fitting the bulb spades well - I don't think they draw a huge amount more, but you can't get more light [and resulting heat] without more amps, and ya never know how much those switch overloads can take, especially replacement ones

I'd try the old bulbs to see if the problem goes away, then check all the connections in the headlight circuit, might be one that can handle the lower candlepower but heats up with higher

Bill

LMC has a heavy-duty headlight harness thats suppose to solve the heavy draw problem. Part#36-3580 for 47-57 and 36-3581 for 58-59,price 29.95 plus shipping.

My truck is a 62, but I will check the catalog