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Discussion Starter #1
my volt meter barely dips when i'm playin my music. which consists of 300 watt amp for highs and 1500 for my 2 12in subs. i also have a red top optima battery in the trunk. but whne i turn my AC on...in the day time (no headlights) the meter drops to just under 12volts. and sometimes i can tell the car gets sluggish. if i'm really beatting with the music, it goes down to 11.8 volts. if i turn the AC off it goes back up to 12.5 - 13 volts. i have stock alternator, should i get a 200 amp one?
 
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Discussion Starter #2
You're crossing volts and amps. Consider what you're running when you turn the AC on.

1. compressor clutch
2. HVAC fan
3. Radiator fan <--big power hog.

These cars will get a bit sluggish because of the load of the AC compressor, and the load from the alternator working to feed the additional electrical load caused by the fan. That demand on the engine would be there regardless of alternator size. I don't know if the 200 amp unit would save the day here.
 
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Discussion Starter #3
Are you talking about at idle in Park or at idle in gear? Does it happen when you're going down the road too, or just stopped?

Easiest way to fix the idle in Park or idle in gear issue is just have the PCM reprogrammed to bump the idle speed with the AC on, or get yourself a smaller pulley for your alternator. IMHO, the 200amp alternator isn't worth it, because when I got my stock 140 amp alternator rebuilt, it put out 174 amps on the dyno. It's just a matter of keeping the alternator speed up.
 
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Discussion Starter #4
i've heard the 200 amp alternator puts out more amps when turning faster of course.
so to answer the question, yes its the worst when in gear at a light. but driving, it goes up to about 12 volts on the dot. and doesnt really go anyhigher....i'm guessing because its tryin to recharge 2 batteries instead of just one.
where can i get a smaller pulley from?
 
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I've got one available; they used to be on ebay occasionally but I haven't seen them in awhile. Shoot me a PM or an email and we can work out the deal.
 
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Discussion Starter #8
Cables most likely aren't going to solve your problem - the issue is simply generating the power you need to run that load. If you really want to verify, setup the car in the condition where it's happening (like engine idling in gear with AC on and stereo going), then check the voltage at the alternator, then at the two batteries. If the voltage is significantly higher at the alternator than at the batteries, I'd check and clean all the connections first, and see what that does. Then, if you are still seeing a significantly lower voltage at the batteries, I'd replace the cables.

Otherwise, I still maintain that the cause is with the power generation (alternator speed), not the distribution (cables).
 
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