# Help with alternator!



## ls2_beast (Nov 24, 2009)

Like 2 months ago my "check alternator" light would come on then turn back off after about 10 seconds about once a week but i never really paid any attention to it until one day the light never came off. I took it to a local auto electric shop to get it looked at and they told me that it looks like the regulator was going out. They went ahead and rebuilt the whole alternator besides the pulley mechanism that goes inside because they could'nt get their hands on one, at least that is what they said. They also checked the battery and everything tested ok. Well the "check alternator" still comes on, I took the alternator to a different electric shop and they also told me that the alternator is testing good. They test the wire coming from the computer and said that the computer was fine since it was sending 5v from one of the wires. What is strange is that the light only comes on when im driving in small streets or im stopped, once I jump on the highway the light comes off. I hope someone can tell me what might be wrong with my goat.. by the way I also bought a new battery to be on the safe side.


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## Poncho Dan (Jun 30, 2009)

Maybe you have one of those silly SLP underdrive pullies?


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## pocketmaster (Feb 26, 2010)

ls2_beast said:


> Like 2 months ago my "check alternator" light would come on then turn back off after about 10 seconds about once a week but i never really paid any attention to it until one day the light never came off. I took it to a local auto electric shop to get it looked at and they told me that it looks like the regulator was going out. They went ahead and rebuilt the whole alternator besides the pulley mechanism that goes inside because they could'nt get their hands on one, at least that is what they said. They also checked the battery and everything tested ok. Well the "check alternator" still comes on, I took the alternator to a different electric shop and they also told me that the alternator is testing good. They test the wire coming from the computer and said that the computer was fine since it was sending 5v from one of the wires. What is strange is that the light only comes on when im driving in small streets or im stopped, once I jump on the highway the light comes off. I hope someone can tell me what might be wrong with my goat.. by the way I also bought a new battery to be on the safe side.


Are you sure your battery is good?? Sounds to me like your alternator is putting out the juice, but the battery may be knocking it down. Thus when your at idle or at low RPM's your alternator cannot compensate for the draw the battery may be putting on the system. If you have access to a multimeter check your battery when the vehicle is turned off and has sat for about an hour. It should read around 13 VDC. If its hovering at or below 12 VDC your battery isnt holding a charge. If it is at or around 13 VDC start the vehicle and check the battery again. It should be over 14 VDC. This is the voltage coming from the alternator to charge the battery. If it is not at or above 14 VDC then your alternator is shot. If your battery is shot it will cause your alternator to eventually go out, as it trying to draw more current from the alternator, thus putting more strain on it. On the same note, if your alternator is bad and your battery is good, evetually your battery will go out due to too much strain upon startup without being sufficiently charged.


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## ls2_beast (Nov 24, 2009)

Poncho Dan said:


> Maybe you have one of those silly SLP underdrive pullies?


I dont have any underdrive pullies


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## ls2_beast (Nov 24, 2009)

pocketmaster said:


> Are you sure your battery is good?? Sounds to me like your alternator is putting out the juice, but the battery may be knocking it down. Thus when your at idle or at low RPM's your alternator cannot compensate for the draw the battery may be putting on the system. If you have access to a multimeter check your battery when the vehicle is turned off and has sat for about an hour. It should read around 13 VDC. If its hovering at or below 12 VDC your battery isnt holding a charge. If it is at or around 13 VDC start the vehicle and check the battery again. It should be over 14 VDC. This is the voltage coming from the alternator to charge the battery. If it is not at or above 14 VDC then your alternator is shot. If your battery is shot it will cause your alternator to eventually go out, as it trying to draw more current from the alternator, thus putting more strain on it. On the same note, if your alternator is bad and your battery is good, evetually your battery will go out due to too much strain upon startup without being sufficiently charged.


I went to auto zone and took my battery for a test,and they told me it was bad, so I went ahead and bought a new battery and the light still comes on. I am going to put the volt meter when I get home to see how much voltage i am getting out of the battery. Thanks


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