headlights dimming

[supmet]

I just noticed today that if I have my stereo up, my lights dim. Its not a ton, but enough to notice. I have 1 or 1.5 farad capacitor, 6 or 700 watt amp to a 400 watt sub.(I'll check later to make sure, ya I know, I really know my stereo huh) Stock alternator and battery with 78k. When I first installed it I turned the gain up higher than it is now, the bass higher, and turned it up loud, in the garage with the lights off, and the lights didn't dim at all, everything else in the car was the same, just newer.

I watched the cap with the stereo up, and it never dropped below 12 and never got above 14. Its old, it was in another car before this for ~20k miles.

Oh, my battery died like a month ago because I sat in the car and listened to music for way too long with the car off, but I haven't had trouble starting since.

So, battery, cap, or alternator? I know I can test my battery at auto zone, but is there any test for the alt or the cap? I have a multimeter.

[YarisSedan]

Battery is only designed really to start the car. Alternator is what keeps it running. At a stop position at idle your alternator is at its weakest. That is when it dips into the battery if something is putting a heavy draw. Which would explain the dimming. Only 2 real ways to fix this now. Have your alternator custom rebuild for higher amperage to power all your stereo system. Or get a deep cycle battery to band aid fix the problem.

Or do what some people do and get both. Maybe try the deep cycle battery first like a yellow top optima.

The battery's that come in our car are very cheap just like the alternator. It barely is enough to run everything. When i had my stereo on and my defroster on at the same time and come to a stop i get dimming cause of the heavy draw.

[supmet]

is 700w really too much for the stock electrical?

[YarisSedan]

I am running a 200W 4 channel amp and i get some mild occasional dimming. And you are running more than 3 times more than me lol so maybe so. If your bass is dipping into the battery constantly its going to take its toll and wear out faster and then your symptoms are going to progressively worse like what you have now. Maybe try taking it to auto zone to have them load test it for you. They do sell deep cycle batterys there too.

I had this issue with my acura when i was running 2 high powered amps. I went through 3 different batterys within a years time. Finally just went and upgraded my altenator and my battery to a optima. That cured most of my problems.

[1NZYaris1]

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[sqcomp]

You could indeed do that grounding kit...

You could also do your Big 3, then replace the alternator with a better aftermarket version if the upgraded grounds don't help. The battery while nice to start the car and feed the amplifiers when the car is off, is not going to solve your system's appetite for Amperage.

[The Architect]

im having a hard time understanding why 700 watts or even a thousand would be noticeably dimming your lights...peculiar.

[Sidicas]

Originally Posted by YarisSedan

If your bass is dipping into the battery constantly its going to take its toll and wear out faster and then your symptoms are going to progressively worse like what you have now. Maybe try taking it to auto zone to have them load test it for you. They do sell deep cycle batterys there too.

I had this issue with my acura when i was running 2 high powered amps. I went through 3 different batterys within a years time. Finally just went and upgraded my altenator and my battery to a optima. That cured most of my problems.

My thoughts exactly.. These batteries aren't meant to be discharged, if you're running a high power stereo system, don't ever run it with the engine off.. Even discharging lead acid batteries to 70% on a regular basis is not good for them.

[supmet]

Well my first guess was the alternator was just going, I didn't think the battery was the main problem, because as was pointed out, its only for starting, but if the battery is on its way out, won't it draw more on the alternator to recharge it constantly?

A deep cycle battery costs about half as much as my whole system did, and I've been wanting to do the grounding kit for a while, and it seems like the cheapest upgrade I can do at this point. I have this thread bookmarked, I just need to find somewhere with good cheap wires.

Originally Posted by The Architect

im having a hard time understanding why 700 watts or even a thousand would be noticeably dimming your lights...peculiar.

Ya, and the fact that it didn't do it new makes me really think its the alternator going.

I guess its off to autozone. I checked their website and it says they do free battery and alternator testing. I've checked salvage sites and there are local alternators for 35 to 60 bucks.. Are there any aftermarket alternators that aren't ridiculously expensive?

Originally Posted by Sidicas

My thoughts exactly.. These batteries aren't meant to be discharged, if you're running a high power stereo system, don't ever run it with the engine off.. Even discharging lead acid batteries to 70% on a regular basis is not good for them.

I usually don't, and if I do, I'm not bumping it.

[The Architect]

iraggi alts could get you a 180amp alt in the factory housing for a decent price. give him a call.

1-615-287-7991

[sqcomp]

These following pages are what you really want to read if you want to know why the headlights are dimming:

http://www.bcae1.com/charging.htm

http://www.bcae1.com/chargin2.htm

Take a look at the rest of the site, it is FULL of information that will help you in the future.

[supmet]

Originally Posted by sqcomp

These following pages are what you really want to read if you want to know why the headlights are dimming:

http://www.bcae1.com/charging.htm

http://www.bcae1.com/chargin2.htm

Take a look at the rest of the site, it is FULL of information that will help you in the future.

Cool, I bookmarked it, and it sounds like my alternator is going after reading the part about dimming lights. It's time to change my belt anyway, I'll try to find a cheap alternator before I do that, I'm still gonna take it to auto zone to get it tested though.

One other thing, I have a tom tom constantly plugged into the 12V, I didn't think it was that big of a draw, but maybe added on to the system(which is 600W, I checked), and recharging the battery from dead, it has slowed the regulator on the alt.

Any idea what an iraggi alternator would cost? I'm planning on adding an amp for the rest of my speakers, and possibly other things down the road, and if I'm just gonna burn through stock alternators, I'd rather just do it right from the start(or at least the next time I have to replace it.. lol)

[The Architect]

i was running two amps and a cap for the longest time with no problems off the stock alt. So long as you're not an ass to your electrical system and monitor voltage the stock electrical will be fine up to around 1000 watts.

As for leaving things plugged in for extended periods of time that draw 12v...dont although Im not sure how youre doing that with the keys out and engine off.

The alt isnt meant to be a battery charger, its a maintainer at best so if anything were to drain the bttery to any worthwhile point and every time you drove the alt had to do extra work then over time this would possibly cause problems.

Here's what sqcomp was quoted from iraggi not very long ago and these prices are pretty good for a quality product.

I just received a whole pricing list from Iraggi:

"Direct bolt on. Same housing as factory.
160 $379
180 $399

Iraggi modded alt. We modify mounting ears to have the same mtg points as factory. Will bolt up almost exactly like factory. This is the one everyone has been doing.

200 $459
220 $479
240 $499
260 $519
280 $539
300 $559"

[supmet]

Originally Posted by The Architect

i was running two amps and a cap for the longest time with no problems off the stock alt. So long as you're not an ass to your electrical system and monitor voltage the stock electrical will be fine up to around 1000 watts.

That's kinda what I thought before all this. I'll see how it handles with a ground kit, and let you guys know if my alternator is in fact going(which is sounding like it more and more)

Originally Posted by The Architect

As for leaving things plugged in for extended periods of time that draw 12v...dont although Im not sure how youre doing that with the keys out and engine off.

I don't without the keys, the tomtom only charges when the keys are in. Its mostly a convenience thing since the tomtom answers the phone for me.

thanks for the price quotes, maybe one day, but I think its a little too much(both money and power) for my system at this point.

[sqcomp]

When I get back in Arpil/May, I'm going to try a Powerbastards alternator. Since our Alty is so easy to get to I figured that with a little communication between myself and the company, much like Arc did with Irragi...I'll give another opinion and possible option for a high output alternator.

[talnlnky]

supmet... your question involves many variables..

here's a list.

Amplifier type (Class D or A/B) D's are around 70-85% efficient, A/B's are 50-60% - most mono sub amps are Class D... most multi-chanel amps are A/B. Therefore... a 400watt sub amp could use the same amount of current as a 75x4 speaker amp does (even though it only pushes 75% as much power)

Wattage of amplifier

Power cable sizes (you have 3 power cables, not just 1, make sure that all of them are at least 4awg.)

Total amperage draw of all amps combined (it has to be matched for the size of power cable you have)

If you run a clipped signal or not (clipped signal = pointless electrical draw,& more distortion, with no added sound volume.... most people run cliped signals due to cranking their gains or bass boost)

If you wait a minute after you start your car before turning on the stereo, and then turn the stereo off a minute before turning your car off. (make sure your bat is fully charged before you turn on your stereo, that way your amplifier will get all power from the alt, instead of sharing with the battery which is still charging.



Alts are the only thing that will help FIX a problem... but there are many things you can do to help REDUCE the problem.... Caps are the icing on the cake... bigger cable, new alt... new bat should all be considered before buying a cap. Frankly, if you have dimming issues, a cap is the last thing you want.... a Cap is a great tool.... for those who don't have dimming issues.

[supmet]

Blaupunkt VA2200
* 700 watts MAX, Class A/B Velocity Series 2-Channel Amplifier
* RMS Power Rating:
o 4 ohms: 200 watts x 2 chan.
o 2 ohms: 300 watts x 2 chan.
o 4 ohms Bridged: 600 watts x 1 chan.
* MOSFET Power Supply
* CEA-2006 Compliant
* Short Circuit Protection and High, Low, Reverse Voltage Protection
* ThermalThrottle Full-on Power Assurance
* RCA Type Input/Output
* Frequency Response: 15 - 50,000 Hz
* 12 dB per Octave, High Pass and Low Pass Crossover

How do I tell what gauge wire I have?

[The Architect]

odds are it'll say right on the wire at some point what AWG rating wire you have.