When I start and while driving my car on, all my lights (interior & exterior) pulsate. The lights do not go off completely, the intensity will increase and decrease about asfast as a heart beat. But when I park my car, turn the key to the "ON (II)" position, and turn my lights on, they DO NOT pulsate. Since the issue only happens when the engine is turned over, could this be an alternator or belt issue? This is in regards to my 2003 Honda Civic Coupe.

 

sounds typical.....
when starting the car the starter PULLS ALOT of power which drops the voltage from 12 to about 11 or less on a older battery which will cause dimming...
and at idle i know that the alternator kicks in and out depending if the computer says its needed or not needed to help conserve gas.

nothing to worry about BUT if you think your battery is old take it to any autozone or advance autoparts or pepboys what ever autoparts store and have them put a battery and alternator test on your car.... most places do it free... just ask them.
they will test it out and tell you if the battery is showing leak or alternator being weak...

 

do you have a system on your car...If you do you will need a good Capacitor. that helps the dimming alot

 

ive said it before and will say it again... caps are crap.....

its all voltage. yyour alternator is kicking out like it was designed to do which cuts your voltage. its VERY COMMON!
even with a high output alternator if it still wires into the computer it will still shut down at low idle and start up.

the best thing you can do instead of buying a crapy CAP...... is upgrade your cars battery! lets face it look at the honda battery they put in these cars.LOL get the largest battery you can fit in that battery slot with the highest COLD CRANKING AMPS and reserve power! and shoe horn that sucker inplace.

ive been around systems for awhile TRUST ME.... if you think CAPS REALY DO WORK then you dont know voltage to well. look at ANY TRUE stereo SPL competitor..... NO ONE RUNS CAPS! its all batteries! batteries STORE power... caps just kinda finger the power and let go instantly without a recharge its worthless.

 

any cap you can afford wont do much good. The dimming is probably coming from a voltage drop caused by resistance in the system somewhere. Its most likely either your battery is old and cheap and has an increased internal resistance at that level of draw or there is a high resistance point somewhere in the circuit acting like a pinch point. I'd start by cleaning and re-attaching your terminal connections and grounds. If that doesn't work, buy a GOOD battery. the new diehard platinums are good, the purelead batteries are better.

 

my friend installed my system and he told me to get a cap, its 1.5 farads, im not going to agree or disagree whetehr caps do anything or not because i dont have to much knowledge on the subject, but my lights dim as well when i crank my system up, i have a jbl 12 inch 1200 watt sub with a 760 watt pionneer amp and it is bridged, i dont know guys... should i upgrade the alternator or the batt.. or should i jus hold it out and see what happens
sry for the hread jack lol

 

Is it ok to add a second battery in the trunk, and wire it in parallel... Like for example, an Optima Red top which is a sealed drycell, with high power out put.... I was just wondering if that was okay for the alternator, I mean does it put more of a load on it to hel keep it charged... or would it in fact help the cars charging system by having more power and in turn reducing the demand on the alternator???

I don't have any problems with dimming unless my amp is running... I run a 1000 watt Sony Xplod on a Kicker Solo Baric S10L7 square sub... no cap, and was thinking of adding a battery, but wondering if it would actually be worthwile...

By the way I have a duralast battery with 650 CA and 525 CCA the original was in the 400's I believe, and it still does it...

 

I also heard of these things called batt caps, which are rapid discharge batteries, that supposedly can provide the power to the amps fast enough that the lights wont dim... something that a standard battery supposedly can't do...

Battcaps are expensive though... do they work?

 

the bigger and better designed the battery is, the more power it can provide. The PHCA is a good indicator of how well the battery will perform powering your subs. CCA is a little outdated but works as an indicator as well. If you parallel two batteries together you can almost double the numbers.

If you put more battery in your car than it was designed for, theoretically the alternator would still work fine IF you didn't use more power than the alternator is designed to provide, but since you're only upgrading the battery because you need more power, you might consider upgrading the alternator as well. (think of the battery as the reserve tank and the alternator as the water source, if you need a bigger tank, you probably need a bigger supply as well)

don't bother upgrading the battery cables unless you start adding crazy power. I saw 2/0 cables for sale at the shop I got my alarm at. I use 2/0 cables on an 800AH battery. You have like a 60AH battery. Unless your cables get hotter than 100f, don't bother doing anything.

caps help if you don't have enough battery for your sound system. They help like a bandaid on a sharkbite. They work because they can discharge almost instantly. the problem is that they still need to charge off the battery. Say your base is pulsing every 1/2 second and has a duration of 1/10 second. The amp needs 100% of that power for that 1/10 second. If you have a large enough cap inline, (capacity equal to the power needed for the pulse), your battery provides 20% of that power constantly instead of 100% of that power 1/5 of the time. ...so.. why not just buy a battery that can meet that peak demand efficiently?

 

Unless you're going to enter one of those "bass-off" competitions where you need every last dB, don't worry about the lights dimming from the amplifier draw. It's not going to hurt anything. Do make sure your battery connections are clean and tight and if the battery is old consider a new one with more capacity.