headlight problem

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Oct 4, 2016
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Location
preston,iowa
My Car
72 mustang convertible.351c 4v bored and stroked,roller cam and lifters,still in process of restoration
[url=https://ibb.co/JkTyQV2][img]https://i.ibb.co/0JLFtTZ/MUSTANG25.jpg[/img][/url]
ok, Im just getting to the point where I am able to drive my car, now on its first run down the street, I have one issue, the lights are on for about 10-15 minutes then just go out. I then can shut them off and turn them back on and they then stay on for about 3-4 minutes then go out. and they just repeat this 3-4 minute intervals. do you think its the light switch heating up? or something else?

 
My guess is bad headlight switch. Mine was doing similar. I replaced and also wired my headlights through a relay to take the load off the switch. No problems since.

 
I think its the switch.  Are you running halogen lights?

kcmash

 
The light switch has a built-in circuit breaker, and that is what is overheating and breaking the connection. The circuit breaker may be weak, you may have a short, or aftermarket headlights, like halogen, may be overloading the circuit. Jason has the best solution. If you do install a relay I would recommend protecting the new circuit with a self resetting circuit breaker, also.

 
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yes I am running halogens, I have orderd a NOS light switch. so now my question is how to wire it to a resistor or relay? if I wire through resistor then what size? and where do I wire that at? I have no electrical experience as you can tell.

 
yes I am running halogens, I have orderd a NOS light switch. so now my question is how to wire it to a resistor or relay? if I wire through resistor then what size? and where do I wire that at? I have no electrical experience as you can tell.
You will wire through a relay, not a resistor. Use the existing headlight wire feed as the trigger for relay and run a separate power that you can pull from the battery but be sure to protect that with a fuse or circuit breaker. That wiring can all be under hood

 
yes I am running halogens, I have orderd a NOS light switch. so now my question is how to wire it to a resistor or relay? if I wire through resistor then what size? and where do I wire that at? I have no electrical experience as you can tell.
You will wire through a relay, not a resistor. Use the existing headlight wire feed as the trigger for relay and run a separate power that you can pull from the battery but be sure to protect that with a fuse or circuit breaker. That wiring can all be under hood
This will work https://www.cjponyparts.com/redline-lumtronix-headlight-power-upgrade-harness-for-two-headlights-1965-1973/p/HVU1/. https://www.rccinnovations.com/index.php?show=menu-hrk-all

 
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yes I am running halogens, I have orderd a NOS light switch. so now my question is how to wire it to a resistor or relay? if I wire through resistor then what size? and where do I wire that at? I have no electrical experience as you can tell.
You will wire through a relay, not a resistor. Use the existing headlight wire feed as the trigger for relay and run a separate power that you can pull from the battery but be sure to protect that with a fuse or circuit breaker. That wiring can all be under hood
This will work https://www.cjponyparts.com/redline-lumtronix-headlight-power-upgrade-harness-for-two-headlights-1965-1973/p/HVU1/. https://www.rccinnovations.com/index.php?show=menu-hrk-all
I bought and installed the CJ Pony harness, for $50 it's hard  to beat. Just faster/easier to spend the money and go plug and play for improved lighting.  Seems safer from a wiring perspective too, especially if you are using your original harness.

I need to do this to my vette too, but the harness it 4X as expensive. I will be building that one myself.

 
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