Why Do Headlights Dim to the Beat of the Music?

[snafu 1099]

1 - Tell me the reason, and explain why

2 - Tell me the solution, and explain why

Let's see who knows their shit.  Go.

[will77530 609]

Your amplifier is drawing amperage than your electrical system can provide 

solution can be a larger battery can be adding. A real capacitor basically giving you a bit more storage for when your alt can’t keep up or upgrade your alt so it can keep up with your current demand 

[bmwking 386 2 Vehicles]

1- Because headlight bulbs are designed to run at full lumen output at ~14.4v.  When your audio system is drawing more current than the electrical system can provide, it lowers the delivered voltage to the headlights (and other accessories) thus lowering the output of the lights.

2- a few solutions.  adding a higher output alternator(s) to boost the available output to the electrical system.  upgrade/add batteries into the system to provide more reserve for when demand presents itself.  upgrade to HID/LED headlights, HID lights store voltage in a ballast to provide a constant higher power to the HID bulb.  LED bulbs use less power to create the same or better output, thus presenting less of a load and operating at lower voltages puts it below the lowest voltage that you're pulling to.

[Joshdashef 217]

I found using LED headlights got rid of my headlight dim. I think its possible to install a capacitor of sorts in line to the headlights to fix the issue with halogens but I'm not entirely sure - probably more trouble than its worth.

[AlpineNut 387]

The Alternator & Battery cannot supply enough juice aka DC / Amps for the entire vehicle when a Amp that is drawing so much current, and it has to be drawn from some place so it starts to dim the headlights as a sign there is way to much current draw happening!

One solution would be to upgrade the Big 4 (shown in video below) so that more DC / Amps can flow impeded, Second would be upgrading the alternator can fix it since it is the main supply for the entire system when running as the battery is just there to help maintain a running engine and help supply any extra DC / Amps needed.  Also adding some extra batteries or upgrading the one under the hood can help some, but a common but unused rule for extra battery's, always try to use the same make since it will work out better, atleast that is what I have read an heard.

 

Edited December 1, 2018 by AlpineNut

[Broke_Audio_Addict 8966]

Electricity takes the path of least resistance.

So in my mind if something is demanding power and is supplied by a big ole wire like an amp would be vs. The headlight wanting more power through the anemic little factory wires then the big ole power wire wins that battle.

I think adding an upgraded relay kit with some fat power wires to supply power to the headlights is one way to improve this problem.

 

Also, halogen bulbs are extremely sensitive to voltage swings.

Edited December 2, 2018 by Broke_Audio_Addict

[Broke_Audio_Addict 8966]

1 hour ago, AlpineNut said:

The Alternator & Battery cannot supply enough juice aka DC / Amps for the entire vehicle when a Amp that is drawing so much current, and it has to be drawn from some place so it starts to dim the headlights as a sign there is way to much current draw happening!

One solution would be to upgrade the Big 4 (shown in video below) so that more DC / Amps can flow impeded, Second would be upgrading the alternator can fix it since it is the main supply for the entire system when running as the battery is just there to help maintain a running engine and help supply any extra DC / Amps needed.  Also adding some extra batteries or upgrading the one under the hood can help some, but a common but unused rule for extra battery's, always try to use the same make since it will work out better, atleast that is what I have read an heard.

 

Ive actually seen the big 3 or 4 upgrade make the problem worse on more than one occasion.

[snafu 1099]

Who else?  Thus far, nobody has answered both questions correctly.

I'll give you a hint.  The headlight is behaving like an analog VOM.  What is it telling you?

[Ahmed Johnson 12052]

That you are driving a pussy magnet? 

[Ahmed Johnson 12052]

I was gonna say it has something to do with HZ but I don't know shit, lol