electrical help f100 1971

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Dec 15, 2013 | 10:50 AM

trickpats

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electrical help f100 1971

hey so as im driving down the road my headlights and dash lights will dim and get brighter. i dont know what it is. any help is appreciated

Dec 15, 2013 | 11:24 AM

Gembone

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is it a pulsing or and immediate change? if pulsing look towards your alt and voltage regulator, and possibly the connector on the headlight switch. if immediate then look to the headlight switch and or connector.

Dec 15, 2013 | 11:27 AM

trickpats

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what do you mean by immediate change?

Dec 15, 2013 | 11:29 AM

Gembone

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flicker, hit a bump it instantly is brighter or dimmer.
a pulse would be slowly changing from one into the other.

Dec 15, 2013 | 11:36 AM

trickpats

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its a pulsing i can be sitting in the driveway and it will flicker on the garage door

Dec 15, 2013 | 11:45 AM

Gembone

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check the plugs and connections for the voltage regulator and headlight switch, possibly even the floor dimmer switch.

Could be a corroded or loose connection. Maybe someone else will chime in with more suggestions.

Have you put a meter on it while running to see if you have steady amps and voltage?

Dec 15, 2013 | 12:27 PM

HIO Silver

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From: NorCal

Check the grounds... extra grounds are also a good idea.

Check all connections but the usual suspect of pulsating headlights is the voltage regulator.

A recommended upgrade is to relieve the ignition switch of the headlights and use relays to directly source voltage from the battery. The headlight "on" signal is then just used to trigger the relays and the result is more efficient voltage and therefore, brighter lighting.