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Discussion Starter · #1 ·
Today my Caprice has been having a rough idle at stops and the volt gauge is only at 50% but with the AC on it drops down to 30-40%, the rough idle gets worse and Performance was very bad. It did rain but the rough idle was present before the rain started. I got to autozone checked the battery and alternator they said it was good. No check engine light. I tried reading my haynes repair manual and the sticky but cant find a solution/problem for these symptoms. The only thing that came to mind is that I'm running a civilian caprice alternator in a 9c1. I hope Im just over reacting and my opti is just wet.Would a wet opti draw more voltage? Why is the AC dropping the volt meter so much? Could It be related to my sub woofer and amp?

It's a 95 Caprice 9c1. New fuel pump in just yesterday, fuel filter 5 months old, New TPS 5 weeks old, and home made CAI added just 5 days ago.
It's been driving me insane someone please help.
 

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the use of the dash indicator gauges are not exact. so you see the volt gauge is lower than normal. what you then do is buy a volt ohm meter and measure the volts at the battery. then you measure at the alternator output wire. if you have 13.75-14.5 volts and the engine is at normal operating temperature the alternator is good. if the voltage is lower then you have a problem with the alternator.

if your voltage is 11volts or lower , the engine and ac will not work very well. with high powered amps the alternator gets heat damaged and fails much faster than with no high current aftermarket devices. the use of farad capacitors helps reduce current surges that will effect vehicle electrical components.

the ac on uses more electrical power so that is why the engine will run worse if it is an electrical supply issue. the battery should also be tested. this is done with a load tester on a fully charged battery. so before testing it use a charger first on it.

check all connections including the one at the under hood fuse box for and heat damage/corrosion [green slime]
 

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Discussion Starter · #3 ·
My alternator is fine. I turned on my car in the morning and it was having the rough idle with everything off. After i drove it everything was fine. The moment i turn on the ac it starts to have the rough idle. I changend the alternator to the one i had in by b4u the cable that connects to the alt had some green stuff in it but was not slime. Still has the problem. I think it has somthing to do with the ac system. I also forgot to mention that i disconnected the air pump for the cai dont know if that has something to do with it.
 

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My alternator is fine. I turned on my car in the morning and it was having the rough idle with everything off. After i drove it everything was fine. The moment i turn on the ac it starts to have the rough idle. I changend the alternator to the one i had in by b4u the cable that connects to the alt had some green stuff in it but was not slime. Still has the problem. I think it has somthing to do with the ac system. I also forgot to mention that i disconnected the air pump for the cai dont know if that has something to do with it.
what is the voltage ?
the air pump deleted what about the hose to the air pump this is used to supply filtered air to the pump. so how did you change this just remove hose and leave it off the air pump..

you remove and clean off all the power connections at battery alt fuse box engine grounds and tight ?
 

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Discussion Starter · #5 ·
Well i found out why it was idling so bad, the cold air intake is the home depot pvc pipe mod with a cone filter. The pvc pipe was badly warped after just a week or so of use
I just disconnected the wires that lead to the air pump and i pluged the hose that led to the stock filter box. My voltage meter is at about 50%, Is that normal? For now i just have the stock baffle with the cone filter and air pump still disconnected. Any issues with that set up?
 
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