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I have a 600watt amp, two subs (600rms total + 2000peak total), a 500watt cap, and my lights dim a lot. I was thinking it's either my alternator or my battery (maybe both). I was thinking of upgrading my alternator instead of a factory replacement also. Does anyone know of any good aftermarket alternators? (I have the same...a 2000 ZX3) I'm already saving for an Optima battery.
 

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Mr. Wizard
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well, I'd say it is probably just your battery. I see alot of people come in here and say that they want to upgrade their alternator, when I've seen alot more run on less powerful alternators without problems. I have a 650watt 5-channel amp powering all the speakers and a 10" rockford sub. I have no dimming. And I have no cap. (Gon, I'm not sure that you are powering your subs correctly, since it looks like your amp isn't rated to handle that power load). I had 600watts in my old VW Jetta, no cap, and a much smaller alternator than what the focus has now. No dimming there either. I often wonder about perhaps the wiring causing this problem for some people or perhaps the install. Maybe the quality of the amp is suspect, I'm not sure. But I don't think necessarily running out and installing a new alternator is a prerequisite for car audio. Like I said before, unless you are powering a small city block.
 

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I am Having the same problem as well. When I am driving and my radio is on I wil see my lights dim to the music when I am at a red light. And lately when I am running the heater and My radio at the same time I will experience My lights dimming and my radio turning off momentarily and going back on.

PLEASE HELP
 

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Mr. Wizard
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these all sound like problems with the battery connection, and not the alternator, that or your alternator is going, you shouldn't need to upgrade your alternator to anything higher than you already have. I've seen more run off of less without problems, check your grounds also.
 

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a good ground will make all the difference, but a cap would definetely help out. get a battery, and a cap. should be all you need.

Mike
 

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a capacitor: it stores a little energy kinda like a small battery for when your subs hit deep powerful notes. I have one and my car still has surges in power. I think my alternator sux, and I need a new battery. I'd like a stronger alternator so I could power a small city block if I ever needed to (or at least some household appliances in an emergency), or so I could jumpstart other cars without freaking out about my battery (I've stalled jumping someone else car).
BTW: (OT..sorry) I heard jump starts are bad for our computers. Should we not do it. I leave my jumper cables at home so I can say "nope, sorry, I don't have cables"...lol
 

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Grounding was mentioned before, but here it is again. If you're running that 600w amp, I'd imagine you've got pretty heavy (I'd hope atleast 8-4ga) power cable, but what did you do for the ground cable? Not just between the amp and the chassis, but between the battery and chassis? 600w amp (provided it will actually produce 600w) with a cap, I think you're trying to say .5 farad (caps cannot be rated in watts), shouldn't dim that bad.....

About the jump starting being bad for the computer, improper connection of the cables can be bad for any electronic device on the electrical system. If you follow the proper hookup procedure (usually included with the cables) and use the chassis ground instead of the battery ground on the donor car ( I think, double check with the instructions) it should be fine.... AND, if you do it right, the big spark (and electrical spike with it) when you make the last connection should be minimized.

btw. A stronger battery will not prevent your lights from dimming while the car's running. The lights dim when the system voltage drops from the 13.4v created by the alternator, down to the 12.3 (approx.) that the battery puts out. Granted, a weak battery will allow the voltage to drop even further, and the lights dim even more, but even the strongest battery won't prevent them from dimming at all...
 

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the electrical capacity of cars is reaching the max for 12 volt systems, so in a few years cars will start having 42 volt systems to handle the greater loads from all the electronic devices cars have now days. It is suspect that the alternator is being over loaded with your amps. But check the gauge of wiring like has been suggested. To small a gauge wire and you could catch your car on fire....
 

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all you need is a cap and youll have no more problems !trust us we know!
 

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Do you have any ideas on the capacitor?
Such as what kind to get?
how much it should be able to store?
What is the best placement in the system?

Thnx ahead of time.
 

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Focituner, I'd head off to any electical / electronic place (not Radio Shack, they won't have it)and look for a 16 or 18v (can't remember which is the std.) 1farad cap. If you wanna get a name brand one, it's all the same sh**, just a different pile. 1 farad is 1 farad. As for where to put it, they usually end up out by the amps because that's where the power cables are getting split up anyway. It's not a big deal if you wanna put it out in the engine bay or somewhere remote, but just remember that like any other high current application, the longer the cables, the fatter the cables. If you wanna put it near the amps, (probably the best idea) 8ga cable is fine, as long as the leads between the cap and the power cable are no more than a few feet long.

Just incase you're not familiar with how it should be wired, you wanna run it in parallel with the power cables, ie. positive lead of the cap to the positive power cable, negative lead of the cap to the negative power cable (or ground). Oh, charging/discharging. Grab any 12v device, a light bulb works great. When you're all set to hook this baby up, hook up one of the leads to the cap, and connect (temporarily) the light bulb between the other terminal of the cap, and the lead that should go there. The light will come on, and slowly dim until it goes out. When the light's out, it means the cap is charged, and you can safely remove the light and connect the other lead to the cap. If you just hook it up, you'll get a nice big spark, and probably take out the fuse for your power cable. If you ever need to disconnect the battery cables, you'll need to re-charge the cap before you reconnect the battery cables, or again you'll get fireworks. I always leave a note in the car whenever it goes into the shop, so they know if they need to disconnect the battery to work on the car. If you need to remove the cap, you'll probably want to discharge it. Just remove the power leads, and take your handy-dandy light bulb across the two terminals. Again, light will come on, and then dim until the it is completely discharged. It'd be an awfull suprise to stick your fingers across that thing when it's got a full charge.

Have fun!
 

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I don't know if you've already bought a cap but most likely it won't help you in your situation. the cap isn't creating power. only the alternator can do that by
converting mechanical power to electrical power. the alternator generates the voltage that the cap tries to maintain, if the
cap discharges to maintain voltage to the amp, the alternator must work
to recharge it. so there's still the same strain on the alternator and electrical system. Things that would help are upgrading the wire gauge and ground spots for the 3 main wires (alt to battery battery to engine andbattery to chassis) to 2 or 4 gauge wire. Make sure no connections on the battery are corroded, if none of that helps and your still having headlight dimming go to autozone and have them test and check out your battery and alternator to make sure they're ok, your battery could be the problem, it could have a dead cell in it or something, the optima battery is a good idea if you have often voltage drops, an alt if good if you have constant underpowering/electrical problems, if it's rare occasion that you get a bad voltage drop then a cap would help. good luck.

- Scott
 

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Mr. Wizard
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if cap protects the rest of the electrical system from sudden drops in charge rather than the battery being the device that takes the hit, when the amp calls for more power than can be provided by the battery at one time, the lights would dim until the alternator can in turn replenish the voltage supply, with a capacitor, the excess charge is stored down line from the battery, when the amp calls for more power than the battery is sending, the voltage is drawn from the cap rather than the battery so that the lights won't dim and the battery will then replace the caps lost charge at its own pace (which is fairly quick). Its kind of like having a mini battery down the line, when its full the load on the battery is normal, when its not full, the load is only slightly higher than normal and not enough to dim the lights.
 

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Does anyone know where the Battery/Electrical system is grounded to the chasis in the focus?
 
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