lights flicker

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May 31, 2015 | 09:28 PM

marine09

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lights flicker

All the lights on my 77 f150 ranger fly flicker while the engine runs. They flicker to the rpms of the engine. I have looked all over for bad grounds. I've searched the internet for solutions but to no avail. Any suggestions?

May 31, 2015 | 09:36 PM

JWC 3

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Joined: Dec 2012

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From: Tennessee

Voltage regulator ..
Does it stop when you rev the engine?
My truck has that issue, for years, just annoying .

May 31, 2015 | 09:39 PM

HIO Silver

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From: NorCal

If you mean they get brighter with higher engine RPMs, then that's usually the sign of an old voltage regulator.

My 65 and 68 Mustangs have the same symptom.

May 31, 2015 | 09:54 PM

marine09

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I'm pretty sure I replaced the voltage regulator. It's behind the horn on the passenger side by the battery right?

May 31, 2015 | 09:57 PM

HIO Silver

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From: NorCal

Quote:

Originally Posted by marine09

I'm pretty sure I replaced the voltage regulator. It's behind the horn on the passenger side by the battery right?

Yup.

.... Ya didn't exactly answer the question..... is the condition RPM dependent???

May 31, 2015 | 10:04 PM

marine09

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At higher rpms the lights don't get brighter, they just flicker faster to where you can almost hardly notice it unless you actually look

May 31, 2015 | 10:14 PM

HIO Silver

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From: NorCal

Quote:

Originally Posted by marine09

At higher rpms the lights don't get brighter, they just flicker faster to where you can almost hardly notice it unless you actually look

Then it is RPM sensitive...Clean and reattach the grounds. Maybe add a couple of extra grounds.

Also consider installing a headlight relay harness so the headlights source voltage directly from the battery instead of the headlight switch. It's $30 well spent. I'm gonna bet the old wiring just has alot of built up resistance (load) that is affecting the headlight current.

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Jun 10, 2015 | 01:08 AM

marine09

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Ok so while I was driving the other night I was watching my voltmeter in my dash and it was bouncing all over the place and the more I watched it, I noticed that the lights actually flicker in time with the voltmeter needle bouncing, and when my radio is on, there is static that comes on and off to the same frequency as the lights and voltmeter.

Jun 10, 2015 | 09:10 AM

#10

ZarK-eh

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Joined: Sep 2014

Posts: 862

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From: like subarctic, brrr man!

Sounds like a Voltage regulator/alternator to me.

I think you mentioned a new voltage regulator, what about the alternator?

Also, check the grounds like HIO said ta