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alternator or battery???

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Old 10-28-11, 08:28 AM
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alternator or battery???

Ok so i bought a 94 rx7 a week ago, when i bought it the guy said the alternator was bad and he had just put a new one in. Sometimes randomly when you would first start it the battery light would come on but after it was reved past 2k it would shut off and stay off. He also said the new alternator had a smaller pulley than the original so i figured that makes sense it just dosen't put out much while idling. This morning i go to turn on my car and the battery light was on and running rough the radio would randomly shut off and come back on then i drove it a few blocks and it completely died. Jumped it a few times to get it to advanced autoparts they tested the battery said it had a bad cell, replaced it and tested then tested the alternator said it wasen't putting out any voltage. My guess is the wiring, maybe the alternator wasen't installed properly? Is it worth taking the alternator in to advanced autoparts to get it tested? Also is there any common wiring issue?
Old 10-31-11, 05:00 PM
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One thing you could do is buy an auto parts alternator and throw it in.. if it doesn't fix the problem you can always just return it to get your money back.

Also make sure the battery cables and connectors are on properly and tight.
Old 11-01-11, 11:28 AM
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Well I used a meter to make sure the alternator was grounded properly, which it was. I read the excitation voltage which was reading 5.01 volts which it's supposed to be between 1-3...so I took the alternator off got it tested at AutoZone sure enough it was bad. After terrible customer service and a few hours later I got my money back from AutoZone and got a new alternator from advanced autoparts(much better customer service and only a day wait rather than half a week). Installed and read 14.7volts at idle and 1.03 for the excitation voltage all is good.
Old 11-01-11, 11:53 AM
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MD

Well done. Happy motoring.
Old 11-01-11, 12:17 PM
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Always check your grounds before buying parts, I learned that the hard way. Good thing partsource takes returns
Old 11-01-11, 07:50 PM
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Advance is definitely better than the zone IMO!
Old 11-01-11, 08:24 PM
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Good to hear you got things worked out , but just for the record a smaller alt pulley with a good alt. would make it turn faster making it charge more at idle . Remember the small pulley is being driven by a larger pulley on the eccentric shaft . The smaller the alt pulley the faster it will turn
Old 11-09-11, 08:24 AM
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do the autozone testers for batteries or alternators ever show a 'good' reading?
Old 11-09-11, 09:20 AM
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Originally Posted by gc3
do the autozone testers for batteries or alternators ever show a 'good' reading?
?/\?..IDEA!
my theory would be that since the test is free that they would have a 'secret switch"..lol!!.
The Employee hits that switch and ALL Freakin alternators are Bad,therefore the Customer "sees" his alternator is bad and orders one while he is there!
Old 11-09-11, 10:20 AM
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glad to hear it all worked out. sometimes it can just be a bad ground.
Old 11-09-11, 11:22 AM
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Originally Posted by misterstyx69
?/\?..IDEA!
my theory would be that since the test is free that they would have a 'secret switch"..lol!!.
The Employee hits that switch and ALL Freakin alternators are Bad,therefore the Customer "sees" his alternator is bad and orders one while he is there!
LOL!

Doubt that is the case BUT you never know.
Old 11-10-11, 06:47 PM
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Originally Posted by misterstyx69
?/\?..IDEA!
my theory would be that since the test is free that they would have a 'secret switch"..lol!!.
The Employee hits that switch and ALL Freakin alternators are Bad,therefore the Customer "sees" his alternator is bad and orders one while he is there!
Dave just for the hell of it why not take one down to them that you know is good and have them check it , even go to a couple different places .. I have often thought the same about the battery testers , I have never had one checked at a store but you see lots of old batteries going in and mostly new coming out. What a money maker ,, Sell the dude a new battery , then a couple days later he comes in with the Alt. in his hand , sell him a new Alt. then sell his used battery for 20 bucks out the back door . Maybe could even sneak a starter in when the poor bastard ain't looking ..
Old 11-15-11, 05:20 PM
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enel1221 it sound like a poopy alternator, most of the time when the alternator goes and the owner doesn't take care of the problem, it ends up taking out the battery. The battery light on the dash is a good indicator, however it is also a good idea to check belts (slipping) 99% of the time you will hear, and to check electrical connectors. If you have a multimeter i recomend busting it out, otherwise make sure all the connections are clean, ie battery to alt. batt. ground...ect.
Old 11-16-11, 08:24 PM
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new alt and cables..
Old 11-16-11, 08:24 PM
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i had a similar issue in my eclipse. i kept getting the reman alts. since they had lifetime warrenty but since its next to the downpipe it would heat up and kill the voltage regulator.
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