75 hiboy headlight issue
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75 hiboy headlight issue
I have an issue the headlights in my 1975 f250 hiboy after about 30 min of driving begin to cut on and off not ficker or dim there either on or off i have replaced the high beam low beam switch and the switch on the dash and still it continues to happen any ideas
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Joined: Sep 2012
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Did you check all your wiring? It could be a break in one of your wires. I know if i took a headlight out of my truck i had no lights at all. So if one break in a wire causes one light to fail you loose both lights. I would start there.
Hotshot
Joined: Apr 2009
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From: Stanley, VA
There is a circuit breaker built into headlight switch itself, this is an automatic resetting breaker.
Sometimes, over time the breaker gets weak and trips on and off without reason. But seeing as you have already replaced the switch, it seems that that would narrow it down to two possibilities, either the new switch is also deffective, possible but not probable, or there is a short somewhere in the wiring.
When the lights go on and off, do you hear a "clicking" sound coming from under the dash? The breaker usually will click when it cycles and resets.
The only other thing I could think of would be, like 91turboranger said, a break in the wire, making and breaking contact as you go down the road.
Sometimes, over time the breaker gets weak and trips on and off without reason. But seeing as you have already replaced the switch, it seems that that would narrow it down to two possibilities, either the new switch is also deffective, possible but not probable, or there is a short somewhere in the wiring.
When the lights go on and off, do you hear a "clicking" sound coming from under the dash? The breaker usually will click when it cycles and resets.
The only other thing I could think of would be, like 91turboranger said, a break in the wire, making and breaking contact as you go down the road.
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Joined: Oct 2012
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I agree with the wiring. Pull the headlights out, check the wires going into them, that would be the easiest thing to check first. Look for loose or corroded terminals. Then follow the harness the best you can looking for rub spots/chaffing areas. Turn the lights on with the truck off and wiggle every connector and harness, see if you can replicate the problem.
Post Fiend
Joined: Apr 2008
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From: Big Sky Country
New User
Joined: Sep 2012
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Sweet i need new headlights in the truck. Guess i am going to pick up this also.
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New User
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But if its a wire break why must i i drive 20 to 30 min for the lights to start acting up and no i dont hear any clicking when they go out and even when the truck is parked and off it does it
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Lead Driver
Joined: Mar 2004
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My wires rubbed through right up by the core support. Sometimes it wouldn't do it for a long time then at random they would go out.
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