with the above...rules are that you have to spin the alternator fast enough to keep up with the electrical demands of the car....
low voltage
Thread Starter
Heel & Toe
Joined: Oct 2008
Posts: 24
Likes: 0
low voltage
Need some advice!
I got a new aftermarket crank pulley installed but when the car is idling with the AC and headlights on, the voltage meter goes down to about 12 or lower. Please tell me what I can do to make it charge to the correct voltage. Thanks!!
I got a new aftermarket crank pulley installed but when the car is idling with the AC and headlights on, the voltage meter goes down to about 12 or lower. Please tell me what I can do to make it charge to the correct voltage. Thanks!!
Melting Slicks
Joined: Apr 2007
Posts: 3,290
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From: Willow Springs IL
Melting Slicks
Joined: Jun 2007
Posts: 2,673
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From: Upstate New York
I'm not surprised. I've noticed that even a completely stock car when idling and running A/C, lights, the car's cooling fan is on, etc. that the voltage dips into the mid/upper 13's. Now you are spinning the alternator slower under those conditions and you see the end result.
I guess the question I would ask is: Does doing this for brief periods hurt anything? I would just make sure that you drive the car long enough for the battery to fully charge.
I guess the question I would ask is: Does doing this for brief periods hurt anything? I would just make sure that you drive the car long enough for the battery to fully charge.
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Melting Slicks
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From: Bradenton Florida
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It will start giving you a low voltage warning on the DIC, you have to hit the reset on the gauge pod to get rid of the annoying ringing! One of the reasons I put my car back to stock and eliminated the Mods the previous owner did. There is too much integrated together that a simple mod affects many weird things!
Le Mans Master
Joined: Feb 2007
Posts: 8,514
Likes: 235
From: Currently somewhere in IL,IN,KY,TN,MO,AR,MS,AL, or FL
So why did you want to run the accessories slower? You decided you wanted to drain less power to run the alternator and now you complain the alternator has too little power? You won't have a problem is you run the engine the way that you should with a smaller crank pulley which is on the track never less than 2500rpm. On the street you are going to have a problem.
I think you need to go back and study the mods you want to make a little more before do them. Everything is a compromise. There is no free lunch. If you try to improve one thing you usually make something else worse.
I think you need to go back and study the mods you want to make a little more before do them. Everything is a compromise. There is no free lunch. If you try to improve one thing you usually make something else worse.
Thread Starter
Heel & Toe
Joined: Oct 2008
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Burning Brakes
Joined: Oct 2006
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Le Mans Master
Joined: Feb 2007
Posts: 8,514
Likes: 235
From: Currently somewhere in IL,IN,KY,TN,MO,AR,MS,AL, or FL
A higher amp alternator only has bigger wires to handle more current. Since you slowed down how fast the alternator is turning you need an alternator that is designed for the slower speed not just heavier wires. And when you finally find an alternator that gets you back to where you were on how much power it was putting out, you will also be back to where you were on how much power it was taking from the engine defeating a large part of the purpose of the smaller pulley.
Burning Brakes
Joined: Jan 2008
Posts: 905
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From: BURTON MI
Raising the idle speed 100 rpm should solve your problem.
