How do I fix my headlights dimming?

[bullshit8421]

Hi, I'm running alpine sps-60c's in the front with sps-60's in the back off of an Power Acoustic GT5-2500 at 4 ohms and I have an American Bass XLF 1244 running off of an Alpine MRX-M110 at 2 ohms (only have it pushing about 500 watts right now to sub). I have a stock 90 amp alt and an OEM replacement 580 CCA battery thats only a year old. My headlights start dimming after about 4 minutes of listening to music as I'm driving down the interstate. How can I fix this? Would a newer bigger AMG battery help? I'm kinda on a budget now just bought the sub and HO alts for mazda 6's are very expensive

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[jboy2015]

have you done the big 3? if not, hit up @mylows10 for a kit

 

[A_Contraptions]

Ford escape/ranger/explorer alts fit also to bypass the computer controlled alt BS. They pop up cheap often. There the 3 bolt "L" pattern alt

 

[n2audio 5,000+ posts]

weird that it would change noticeably over time.

Some voltage measurements would be helpful.

Initially, I'm thinking your battery could be the weak link.

Nobody does this - but if the elect. system generally does its job aside from headlight dimming at high volume the cure is to install a small (1/2F) cap under the hood on the headlight feed -- closer to the lights the better. That would absolutely cure dimming.

 

[DaytonLax14 10+ year member]

^^^that solution sounds interesting. Do you have any more information regarding it?

OP, do the big 3 and put an AGM under the hood, the biggest that will fit in your battery tray

 

[wew lad 5,000+ posts]

weird that it would change noticeably over time.Some voltage measurements would be helpful.

Initially, I'm thinking your battery could be the weak link.

Nobody does this - but if the elect. system generally does its job aside from headlight dimming at high volume the cure is to install a small (1/2F) cap under the hood on the headlight feed -- closer to the lights the better. That would absolutely cure dimming.

I've been considering this, i dont mind voltage drop, i just hate how it looks. my tail lights dim too i'm considering buying a few small caps

 

[n2audio 5,000+ posts]

^^^that solution sounds interesting. Do you have any more information regarding it?
OP, do the big 3 and put an AGM under the hood, the biggest that will fit in your battery tray

What else do you need?

Trace a power wire from a headlight, hopefully find the junction with the other light's wire. Splice somewhere near the junction that allows for a workable mounting location. Connect the cap like any other cap installation.

I'm guessing tracing the wire is much easier said than done, but it could certainly be done. Mounting location could be a trick too with some tight engine compartments.

JL mentioned this in their school of sound class.

I've read other experts mentioning it in passing. I think the implication is if dimming is enough of a problem that you need to go to this extent to fix it there is probably something going on with the alternator/battery that needs to be addressed.

But if you're just trying to eliminate minor dimming because you don't like it - a cap on the lights would work.

 

[DaytonLax14 10+ year member]

What else do you need?
Trace a power wire from a headlight, hopefully find the junction with the other light's wire. Splice somewhere near the junction that allows for a workable mounting location. Connect the cap like any other cap installation.

I'm guessing tracing the wire is much easier said than done, but it could certainly be done. Mounting location could be a trick too with some tight engine compartments.

JL mentioned this in their school of sound class.

I've read other experts mentioning it in passing. I think the implication is if dimming is enough of a problem that you need to go to this extent to fix it there is probably something going on with the alternator/battery that needs to be addressed.

But if you're just trying to eliminate minor dimming because you don't like it - a cap on the lights would work.

That's the information I needed haha. Might be a cool weekend project.

 

[SounDrive Pro Seller]

Ho alt, AGM battery under the hood, or add an ultracap bank. Also if you're clipping even slightly you're drawing much more current than needed, so set your gains properly with an oscilloscope preferably.