headlights flickering
New User
Joined: Dec 2007
Posts: 11
Likes: 0
From: Western alaska
Check the wires/socket where the head lights are plugged into. I had a simular problem, the socket was no good. I bought a generic 3 prong plug from Carquest for 5 bucks I think. Problem solved, hope yours is as easy to fix.
MSEE
Joined: Apr 2004
Posts: 10,386
Likes: 35
From: Austin, TX
As you have been told by others, the circuit breaker in the headlight switch is interrupting because of a short downstream. You need to inspect all wiring for frayed or pinched insulation. This must take place regardless of any headlight or relay upgrade you are considering.
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New User
Joined: Dec 2013
Posts: 24
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What is the little black cylinder looking thing called that is mounted beside the voltage regulator? What does it do? Thanks it looks a little burnt up I did find some cracked open wiring and I repaired it but it is still flickering, ughhhhh
MSEE
Joined: Apr 2004
Posts: 10,386
Likes: 35
From: Austin, TX
That's a radio noise suppression capacitor. It has nothing to do with the headlights. Keep inspecting.
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New User
Joined: Dec 2013
Posts: 24
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Seeing as we can not find any breaks or kinks in the wiring my brother seems to think it's a good idea to go get a new voltage regulator he says a wire from it runs the marker lights and he says the voltage regulator could be acting up causing this? What do you think? I'd rather not go get parts I don't need
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New User
Joined: Jan 2014
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I know in my 78 bronco I had flickering lights for months and I couldn't find the culprit, turns out a new voltage regulator fixed it. I was also told they didn't control the lights at all so when it fixed I searched it up and I figured out why it fixed it.
apparently there is a yellow wire (yellowand black I think) that comes off the voltage regulator, I think its the second wire in after the radio capacitor, anyways apparently it controls the voltage to the marker lights which are wired into the lightswitch somewhere along the way, and the cause of my lights flickering ended being from the voltage regulator going bad and giving the lights to much current tripping the breaker in my light switch and doing what it sounds like yours is doing, flickin on and off to no rhythm and doing it still with the engine off, that's what mine was doing.
so to whoever said the voltage regulator has absolutely nothing to do with it it actually does and is probly the culprit since hes already tried everything else
apparently there is a yellow wire (yellowand black I think) that comes off the voltage regulator, I think its the second wire in after the radio capacitor, anyways apparently it controls the voltage to the marker lights which are wired into the lightswitch somewhere along the way, and the cause of my lights flickering ended being from the voltage regulator going bad and giving the lights to much current tripping the breaker in my light switch and doing what it sounds like yours is doing, flickin on and off to no rhythm and doing it still with the engine off, that's what mine was doing.
so to whoever said the voltage regulator has absolutely nothing to do with it it actually does and is probly the culprit since hes already tried everything else
MSEE
Joined: Apr 2004
Posts: 10,386
Likes: 35
From: Austin, TX
Think of it this way. If there truly was not a problem with the wiring, you wouldn't be having this problem. The fact that you're having this problem means there is a problem with the wiring or the bulbs downstream.
Why? I already told you that the voltage regulator has nothing to do with the circuit in question. According to your description, the headlight switch is clicking in sync with the headlights going on and off. That means the breaker is interrupting. The only way this is possible is an over-current condition, meaning a short downstream. The solid reading of 13.76 volts you measured across the battery posts means your charging system is operating normally.
Your brother doesn't know what he's talking about.
Your brother doesn't know what he's talking about.
MSEE
Joined: Apr 2004
Posts: 10,386
Likes: 35
From: Austin, TX
Folks, let's make one thing perfectly clear:
Yes, the situation you described CAN happen, IF the voltage regulator lets the charging system float too high. However, the OP made this claim:
Unless the OP took the measurement incorrectly or did not report any odd behavior, this completely rules out anything to do with the charging system.
I am done with this thread. I have politely explained how the system works multiple times, only to address your tangential questions resulting from ideas that other misinformed individuals plant in your head. You seem hell-bent on replacing your voltage regulator; that's fine, they're $20. Go for it. If that solves your problem, more power to you and I'll be glad to find your vehicle is back on the road.
Your description of the symptoms do not point to a voltage regulator. If you find the voltage regulator does solve the issue, then your description thus far would have been inaccurate. Perhaps you mean something else when you say "clicking" or "flickering." I've told you how things work; the ball is in your court.
Unless the OP took the measurement incorrectly or did not report any odd behavior, this completely rules out anything to do with the charging system.
Your description of the symptoms do not point to a voltage regulator. If you find the voltage regulator does solve the issue, then your description thus far would have been inaccurate. Perhaps you mean something else when you say "clicking" or "flickering." I've told you how things work; the ball is in your court.
Posting Guru
Joined: Feb 2007
Posts: 1,735
Likes: 2
From: Wingo, Ky
Fmc400 is very knowledgeable on this type of thing. If you described your problem accurately I think you will find a new voltage regulator won't help.
Its all in the details. With a good description the problem can be solved.
Its all in the details. With a good description the problem can be solved.
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New User
Joined: Dec 2013
Posts: 24
Likes: 0
I'm trying here lol! So I turn the lights on they work fine for about 10-15 second then start flickering along with a sound coming from the switch (breaker) there is no pattern at all sometimes flickers more sometimes less, I replaced the switch, I check all the wires the best I could I did find some breaks in wire insulation so I repaired it, still is not fixed