I just bought an old Rockford Fosgate Punch HE2 12" sub in an enclosed box. I am powering it with a JL Audio 250/1v2 (which is less than the sub's 400W RMS capability). I have an Optima red-top battery, upgraded ground wires to 4 AWG, and have 4 AWG power wire for my amps (a JL Audio 300/4 for my speakers). Now when the sub hits, my dash lights dim. From talking to uncald4 and reading previous posts, I didn't think I'd have this problem since I have a good battery and good gauge wiring. Any thoughts as to why this is happening?

 

You need a capacitor! Factory alternators are not made to power extra amps. A capacitor will charge up and deliver quicker, more efficient power to your amplifier while taking stress off your vehicles electrical system and in turn helping to stop your lights from dimming. I would say get at least a 2 farad capacitor.

 

Thanks for the suggestion, and I do know about capacitors, but from what uncald4 and others such as wongtsx05 have said, caps are just "band-aids" for the electrical system, and for what I am running and with my other mods (red-top and upgraded grounds) I shouldn't need them.

 

Capacitors are band-aids. I haven't installed one in years. But everyone has their own opinion about them.

Assuming that your REDTOP is good your lights should not be dimming with those two amps running. That battery is a quick charge-quick discharge battery and should have more than enough amperage to sustain a 70 amp current spike. I would have your local auto parts store run a load test on that battery to make sure that it's in tip top. How old is that battery?

 

i have also heard people say capacitors don't do much. but after putting one in my car, my lights don't dim anymore and the amp seems to be getting better power. but like others have said, not everyone likes them

 

2-3 years

I'll get the battery checked out, thanks for the suggestion!

 

When you upgraded the grounds, did you upgrade the power wire from your alternator to your battery?

 

No I did not, just the 3 main negative grounds. I will upgrade the alt to battery wire to 4 AWG and I'll see if that makes a difference. Thanks for the suggestion!

 

The grounds will help a little bit, but it's the power wire that is the most important one in what's called the Big 3 upgrade (alt+ to bat+, bat grounds, alt ground)... My 1st gen CL's alt+ to bat+ was maybe 12g but probably smaller... I replaced it with 1/0AWG and it did wonders...

 

yeah switching the wires to the alternator helps.....as far as the capacitors it really doesnt do much for ur lights

 

Don't get caps, they're pointless...

I would run 0ga from your battery to your trunk, then use a distro block and split it into 2 runs of 4ga. Also do the Big 3 (i'll explain...)

1. Alt to pos on battery (i always run an inline fuse close to the battery on this run)
2. neg on battery to chassis
3. chassis to engine block

Use 0ga wire...

I think these few things will definatly stop you from dimming...

If you need a more detailed step by step info, just let me know. I have yet to do this to my TL, but once I do...I'll have a nice how-to on it

 

sorry mattastick, didn't see your post...

 

heres a thought u can just do a second battery thats the setup i have one my car

 

Very true bucsteve...I've run extra batteries in the past two cars I've had. With the amount of amperage he is pulling tho...another battery isn't necessary (although it wouldn't hurt anything either)

 

very true....i would go with doing "the big 3" first then if that doesnt work maybe a 5 farad cap

 

Im having the same problem. I have a 1350 watt RMS system with a 2 farad cap and a big 3 upgrade with 1/0 wire. I am running on an OEM rated battery though and I fell that this is where my problem lies.

Although 550 watts seems a little light to make the lights dim especially with your upgraded ground wires.

If your battery does test bad I would replace it with a yellow-top because they're made to handle audio systems better than red-tops.

 

It's all good TypeSinNC. As for a second battery, it's only necessary if you play the system with the car off a lot. If your Red Top is bad, also maybe consider a car audio battery for the front. I just picked up a Powermaster D5100R and it made a big difference, even though i turned my gain up (from ~800w to 1200w) due to my new sub. Anyway, the 1/0 is a good idea... It'll help your amps too, as they'll get more current than with the 4 you have in there now...

OP, you're going to have a PM in a couple mins as well...

 

Thanks for the help, guys. mattastick, I'm going to try to upgrade my alt to battery wire with some leftover 4 AWG and see how that works first before upgrading to 0/1.

 

get a capacitor asap. you will risk the chance of blowing your altanator if you keep bumping it without one

 

True dat! You might blow a head gasket too.

 

1. Caps are retarded.
2. Redtops are starting batteries.
3. Caps are still retarded
4. Get a yellow top.

 

Im willing to bet your sub is wired at ohms that your amp cannot handle. Ive had this problem before except my amp would run for like 30 minutes, cut out go into protect then come back on, it was running at less then one ohm and my lights dimmed like a mofo. Check what your subs voice coil(s) are rated ohm wise and check what the lowest ohms your amp can handle, then look up a wiring guide on craigslist that suits your system, if you want the most power try to stay in 1-2 ohm area