alternator
Thread Starter
Burning Brakes
Joined: May 2001
Posts: 1,036
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From: Plant City Fl
alternator
Installed new alternator today, what should the volt reading be at idle, 600rpm and at driving speeds. Should they be about the same, or will the voltage drop considerable when idleing. Thanks in advance.
Team Owner
Joined: Sep 2001
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From: Athens AL
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Re: alternator (Bob88Convertible)
After you crank it, when the engine is cold, it should jump the low/mid 14s.
When hot, that will drop to the mid 13s. Like 13.5-13.7 for mine.
At idle, if you have alot of stuff on it might dip to the high 12s (lights, AC, radio) but if not it should stay above 13. My new one stays 13.3 at idle.
When hot, that will drop to the mid 13s. Like 13.5-13.7 for mine.
At idle, if you have alot of stuff on it might dip to the high 12s (lights, AC, radio) but if not it should stay above 13. My new one stays 13.3 at idle.
Team Owner
Joined: Mar 2000
Posts: 83,383
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From: Boston, MA
Re: alternator (vader86)
In order to maintain proper charger on your system you want to see 13.9-14.1 at all times. I have found that the dashboard typically displays 0.2 lower than what the alternator is truly putting out.
Thread Starter
Burning Brakes
Joined: May 2001
Posts: 1,036
Likes: 0
From: Plant City Fl
Re: alternator (Bob88Convertible)
Wow, I'm not seeing that at all. Its at 13.2 while driving, drops to low 12's at idle, went into 11's a couple times. Could it be the belt is a little loose?? I'll have to check that tomorrow. Anything else.???? Thanks.
Team Owner
Joined: Mar 2001
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From: Cincinnati, Oh USA
Re: alternator (Bob88Convertible)
When the engine is idling, the alternator rpm is also low and it cannot deliver its rated current. If you have a large electrical load (a/c, radio, lights, etc), the alternator voltage will fall to where the battery is supplying a good portion of the current and your dash voltmeter will read below 13 volts. This is not harmful and the battery will be replenished and the voltage rise when you get underway. A low percent of driving involves the engine idling. As long as the red battery symbol doesn't light up on your dash (alternator has no output ), you needn't worry.
Pro
Joined: Mar 2002
Posts: 726
Likes: 1
Re: alternator (scorp508)
In order to maintain proper charger on your system you want to see 13.9-14.1 at all times. I have found that the dashboard typically displays 0.2 lower than what the alternator is truly putting out.
12.8V at the alternator is battery voltage. If you are dropping below that point you are actually pulling current from the battery - and if you top out at 13.2V while driving, you will never restore that charge. :nonod:
You need to take your car to get the electrical system checked out! :yesnod:
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