Flickering headlights when voltage drops

[Thatguy1455]

Hey guys, Im a new member on here. I've got a few problems on my Explorer i've been trying to fix. Mainly my flickering headlights. I do have a good powered system, but even when I first started off with low power, my lights would randomly flash while i'm driving. Like i'm trying to flash someone. Its all lights that would turn on as if the switched was on. Headlights, fogs, dash, tail lights, etc. What could be the cause? Bad alternator? Wiring?

 

[pbnj22]

You nailed the problem with your tite.. the voltage gets too low to supply power to your headlights. the fix would be to get a "high output alternator" and 1 or more better batteries

and by the way what is considered a "good powered system?" what size wiring are you using? google "the big 3" which is increasing your wiring size from alternator to battery, battery to engine ground, and battery to chassis ground. that would be a good start.

 

[DjDom]

You nailed the problem with your tite.. the voltage gets too low to supply power to your headlights. the fix would be to get a "high output alternator" and 1 or more better batteries

and by the way what is considered a "good powered system?" what size wiring are you using? google "the big 3" which is increasing your wiring size from alternator to battery, battery to engine ground, and battery to chassis ground. that would be a good start.

Wow this advice is bad..

Start with something simple. Does it happen only when the lights are on, or does something else have to be on too. Have you checked battery connections? Sometimes corrosion on the battery terminal or the body ground point can cause flickering.

 

[pbnj22]

How is that bad advice? he said it only flickers when the voltage is low. thus fix the voltage and problem goes away..my guess (which at this point is as good as yours) was that the voltage dropping was due to the extra strain on the electrical system caused by the amp. or his electrical (alternator and battery) isnt up to par but since he didnt list any other driveablitly symptoms or being able to start his car in the morning i would have to guess his battery and alternator are fine (for now.)

 

[Thatguy1455]

Ok. I have the big 4 done and running ofc 0 gauge. All ground points are good. Got a hifonics 1600 pulling140 amps and I know the alt is 130 so I know there will be little draw. But I have a xs power battery in the back but the thing is constantly sitting at 14.4-.3. I'll occasionally drop to the 13s but like I said while I'm
Driving and the alternator is charging the system at 14.4 they flicker. I have the auto dim rear view mirror on the Eddie Bauer. And everytime they turn on there's a green light in the rear view that flashes when the lights do. Sorry about leaving out some details in the first post. Plan on getting a mechman 270 in the near future.

 

[Thatguy1455]

Also DjDom, it happens when the headlights are both on and off. No ac, or anything that draws power other than the amp and the engine. Usually drive with windows down. Also have upgraded battery posts. And PHN I meant like not a amp that pulls a lot of power from the battery/alt. had a starter kenwood amp at first

 

[DjDom]

Hmm, how's that secondary battery wired. Is it just a direct connection to the primary or is it separated? Sounds like the alternator just can't keep up with charging 2 batteries.

I apologize pbnj, but no where prior did he state the amount of power his system was drawing.

 

[Thatguy1455]

Yes DJDom, it's directly wired from the front to the back and it's grounded to the back to a distribution block

 

[pbnj22]

Ok. I have the big 4 done and running ofc 0 gauge. All ground points are good. Got a hifonics 1600 pulling140 amps and I know the alt is 130 so I know there will be little draw. But I have a xs power battery in the back but the thing is constantly sitting at 14.4-.3. I'll occasionally drop to the 13s but like I said while I'm
Driving and the alternator is charging the system at 14.4 they flicker. I have the auto dim rear view mirror on the Eddie Bauer. And everytime they turn on there's a green light in the rear view that flashes when the lights do. Sorry about leaving out some details in the first post. Plan on getting a mechman 270 in the near future.

okay so you occasionally drop to the "13's" that would mean your still technically charging your batteries. batteries rest at 12.6 ish so anything over that is charging and anything under that is a draw. soooo if your sure you do not go below the 13s I would almost rule out your amp and audio stuff as the culprit. i thought when you said they flicker with voltage drop you meant like voltage dropping to like 11 or something..

do they flicker more with ac on and while the music is turned up loud?
if its the same through out then i would suspect some kinda wiring issue behind the dash and to your headlights.. maybe try installing a relay?

 

[Thatguy1455]

It's also when the ac is on. Weird. And also It messes with my gas. One day I can have 50 something miles til empty and then it'll shoot up to 130. Stuff like that. I know I need to replace my cps but that shouldn't effect the accessories should it?

 

[koda2000]

with all accessories and lights turned off, you should be seeing about 14.3-14.5 volts as measured across the battery terminals with the engine idling. anything much less than that i'd say your alternator isn't putting out 100%. this could be due to a bad diode or bad voltage regulator. if you're going to replace the alternator, i'd look for something with more amps than the stock 130A if you have a big sound system.