lights flicker

Reply Subscribe

Thread Tools

Search this Thread

May 31, 2015 | 09:28 PM

marine09

Thread Starter

Freshman User

Joined: Feb 2014

Posts: 29

Likes: 0

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

Lead Driver

Joined: Dec 2012

Posts: 7,870

Likes: 47

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

Fleet Owner

Joined: Dec 2009

Posts: 20,678

Likes: 82

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

Thread Starter

Freshman User

Joined: Feb 2014

Posts: 29

Likes: 0

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

Fleet Owner

Joined: Dec 2009

Posts: 20,678

Likes: 82

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

Thread Starter

Freshman User

Joined: Feb 2014

Posts: 29

Likes: 0

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

Fleet Owner

Joined: Dec 2009

Posts: 20,678

Likes: 82

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.

Ford's 2001 Explorer Sportsman Concept Looks For a New Home

Verdad Gallardo

10 Best Ford Truck Engines We Miss the Most!

Joe Kucinski

2026 Shelby F-150 Off-Road: Better Than a Raptor R?

Brett Foote

2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!

Michael S. Palmer

10 Most Surprising 2026 Ford Truck Features!

Joe Kucinski

Top 10 Ford Trucks Coming to Mecum Indy 2026

Brett Foote

5 Best / 5 Worst Ford Truck Wheels of All Time

Joe Kucinski

Ford Super Duty: 5 Things Owners LOVE, 5 Things They LOATHE!

Joe Kucinski

Every 2026 Ford Truck Engine RANKED from WORST to FIRST!

Michael S. Palmer

The Best F-150 Deal of Every Trim Level (XL through Raptor)

Joe Kucinski

Jun 10, 2015 | 01:08 AM

marine09

Thread Starter

Freshman User

Joined: Feb 2014

Posts: 29

Likes: 0

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

Elder User

Joined: Sep 2014

Posts: 862

Likes: 7

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