Lights dimming

[vsolara]

Hello! I recently finished my first subwoofer build.

Headunit: Pioneer DEH-2100IB

Sub: 12" Alpine Type R (4ohm DVC)

Amp: Alpine MRP-M500, runs 500W to sub

The system is great, it blows me away. However, at night the dashboard lights dim a decent amount. I get some head light dim, not enough to impede driving but if you look for it you can notice it.

Currently I only have 8 guage wire, but I'm planning on replacing it with 4 guage. Will this help any? I was also thinking about getting a capacitor for it. I understand these don't provide any more power, but would it put less strain on my electrical system?

Another thing, if I continue to use my current system does it hurt the battery or alternator (or both?).

Thanks!

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[*SlappinAzz*]

Bad grounds will do that.

Upgrading power wire to 4 gauge will fix it as well.

And go to the hood of your car, and run a 4 gauge ground, from the frame to the negative side of the battery.

 

[gboo559 10+ year member]

Upgrade to 4 gauge(if your amp accepts 4 gauge wire)

You shouldn't have dimming with 500rms imo, if you still do, do the big 3 upgrade in 1/0.

 

[misfit138 5,000+ posts]

Buy the 4 awg power & ground wires. If you still have dimming issues, perform the big 3 upgrade.

 

[misfit138 5,000+ posts]

Upgrade to 4 gauge(if your amp accepts 4 gauge wire)
You shouldn't have dimming with 500rms imo, if you still do, do the big 3 upgrade in 1/0.

beat me to it.

 

[SRim23 5,000+ posts]

What car do you have? Main thing is to make sure you have a good ground. if you think its good, re do it! read up on what a ground should be and make sure you fit all the criteria. this seems simple, but there are alot of problems beginners run into that are just simply a bad ground.

And yes, if you are seeing huge voltage drops your battery will be drained and your alternator will be strained. but again, this shouldnt be happening with only 500 rms. so either your battery was already weak and going bad before you hooked up the system, or your grounds just need to be a little better.

 

[gunz4me2 10+ year member]

Maybe it would help to know what vehicle/alternator the OP has before haphazardly throwing the "Big 3" upgrade out there. If the OP is running some 4 banger econobox with a 65 amp alternator, that doesn't leave much additional charging voltage to run the car, headlights, AC, AND sound system. If he indeed has a micro alternator, the Big 3 will do NOTHING to help the dimming situation.

 

[vsolara]

Alright, thanks a lot for all of your quick responses. Assuming I upgrade to the correct guage wire, you all are saying that I shouldnt need a cap at all, right? I didn't plan on buying one initially (the system is somewhat modest at 500W).

[edit] I have a 2001 toyota solara with stock 80 amp alt. Also the battery is only a few months old (however it isnt a high performance model, just a $100 one)

 

[*SlappinAzz*]

Alright, thanks a lot for all of your quick responses. Assuming I upgrade to the correct guage wire, you all are saying that I shouldnt need a cap at all, right? I didn't plan on buying one initially (the system is somewhat modest at 500W).

Caps are shit. Never get one. Upgrade the wire, and if it still dims, just do the big 3 in 0 gauge. Also couldn't hurt to put a small battery in the back. =)

 

[misfit138 5,000+ posts]

Also couldn't hurt to put a small battery in the back. =)

shouldn't be necessary.

 

[SRim23 5,000+ posts]

With your battery being new then that shouldn't be an issue. If you were running 1,000 rms or more then we might need to upgrade the battery. Your issues should be solved by simply upgrading your ground, if not then by upgrading your wire.

 

[vsolara]

Thanks a lot to everyone, I'm glad it sounds like I wont need a cap. Can anyone suggest a resource that describes how to get a good ground? Right now I just have an existing hole that I used a nut/bolt to connect the O-terminal to (of course I sanded the paint first).

 

[*SlappinAzz*]

Thanks a lot to everyone, I'm glad it sounds like I wont need a cap. Can anyone suggest a resource that describes how to get a good ground? Right now I just have an existing hole that I used a nut/bolt to connect the O-terminal to (of course I sanded the paint first).

Near the amp, usually seats bolt to the floor work.

For the big 3 ground, do it from the strut tower bolt, to the battery negative.