Headlights blink

[TX '73]

After the truck warms up my highbeams start blinking. Doesn't matter if the truck is moving or still. The lowbeams don't blink any. I was advised to replace the dimmer switch, did that. Then I replaced the light switch but still have the problem. It could be a loose ground but I don't see how if it blinks when the truck is parked (no bumps). I looked for a loose wire but didn't find one. I also looked for a damaged wire but found nothing. Could it be a voltage regulator going bad? Not sure what else to do. The truck probably needs to be rewired but I can't take that on just yet. Any suggestions?

 

[76Explorer]

After the truck warms up my highbeams start blinking. Doesn't matter if the truck is moving or still. The lowbeams don't blink any. I was advised to replace the dimmer switch, did that. Then I replaced the light switch but still have the problem. It could be a loose ground but I don't see how if it blinks when the truck is parked (no bumps). I looked for a loose wire but didn't find one. I also looked for a damaged wire but found nothing. Could it be a voltage regulator going bad? Not sure what else to do. The truck probably needs to be rewired but I can't take that on just yet. Any suggestions?

If you have upgraded your headlight to higher wattage bulbs, then your headlight switch is overloading, thus kicking off and on. See attached link http://www.bronco.com/cms/node/65

If you didn't upgrade, then check all of the ground wires that pertain to running and headlights.

 

[Big Country]

i have found that connector at the back of the headlight can give you alot of problems i would check that too.

 

[Broncoholics]

Are they just flickering or blinking on and off? Most times its a bad ground. Who knows what previous owners have done. You have to trace and look around. I remember one time adding a ground cable from the engine to the body and then from the body to frame. This fixed my rough running motor and my flickering lights for $5. Couldn't believe it. The body has a hard time grounding itself without it.

 

[TX '73]

Are they just flickering or blinking on and off? Most times its a bad ground. Who knows what previous owners have done. You have to trace and look around. I remember one time adding a ground cable from the engine to the body and then from the body to frame. This fixed my rough running motor and my flickering lights for $5. Couldn't believe it. The body has a hard time grounding itself without it.

Yea they're blinking on/off on/off, not flickering (even when truck is motionless). I still don't know why it happens only after the truck has been running for 15 or 20 minutes??? That's a bit puzzling at least to me.

I haven't upgraded the headlights, they're plenty bright (when they're working), however I've only had the truck for about a year so I really don't know for sure if they were upgraded before I got it or not, until I look closer.

Is big country talking about the spring behind the lamp?

Thanks everyone, I'll let you know how this turns out........

 

[desisbronco]

Yea they're blinking on/off on/off, not flickering (even when truck is motionless). I still don't know why it happens only after the truck has been running for 15 or 20 minutes??? That's a bit puzzling at least to me.
I haven't upgraded the headlights, they're plenty bright (when they're working), however I've only had the truck for about a year so I really don't know for sure if they were upgraded before I got it or not, until I look closer.

Is big country talking about the spring behind the lamp?

Thanks everyone, I'll let you know how this turns out........

Voltage regulator might be the trick...its simple

 

[BlueJ7]

I've had that problem too and I changed out my dimmer switch and it still did it so I just cleaned the contacts and it hasn't done it again.

 

[natecollins]

this same problem happened to me earlier this year. it is the headlight switch. i replaced the switch w/ a cheap switch and it started happening again. get yourself a good switch and you shouldn't have any problems.

 

[TX '73]

Hey guys, I regrounded the headlights but it didn't fix the problem. I installed a new voltage regulator and I think it fixed it. I drove it with the highbeams on for about 30 minutes and no blinking. I guess it was the voltage regulator after all. Thanks...