1994 Saturn SL2 is my new alternator bad

Tiny
SHAGGYBOB2KK
  • MEMBER
  • 1994 SATURN SL2
  • 4 CYL
  • FWD
  • MANUAL
  • 150,000 MILES
I recently replaced my alternator a few weeks ago. The voltage with the engine running was at about 14. No problems for three weeks. Today the battery light came on and I checked the voltage again. I went from the back of the altenator to chasis ground and got just under 12 volts-same as battery. Does this test rule out the fusable link? I checked the same voltage test with the car running and no change- I'm thinking the alt is bad. Any other tests to narrow the possibilities I may not have thought of?
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Friday, July 16th, 2010 AT 5:14 PM

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Tiny
SATURNTECH9
  • EXPERT


http://www.2carpros.com/forum/automotive_pictures/416332_1994_sl2_alternator_wire_diagram_part1_1.jpg


First of all thank you so much for your donation.It sound's like you have a another bad alternator.But let's check a few thing's with the car idling what is the voltage at the battery cable?Also you should have battery voltage to the stud the fuse link goes too.Also on the connector to the alternator you want battery voltage going to the brown and white wire if you have those two things and the alternator is spinning then you should be charging.Let me know what you find.
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Friday, July 16th, 2010 AT 5:33 PM
Tiny
SHAGGYBOB2KK
  • MEMBER
Your welcome -thank you for the prompt response !At battery cable voltage is same 12v. The stud the fuse link goes to; are you refering to the wire on the back of the alternator with the boot cover? If so thats also 12v. (Same when engine is off) I was unable to check the brown & white wires tonight as I put evrything back together( I dont have a lift or sturdy jack so I tested through the wheel well )but the alt is spinning and the tension on the belt is good. Shouldn't I be seeing a voltage increase to about 14v at the alternator if it was charging or would that only show at the battery? When I remove the neg from the battery while idling she dies.
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Friday, July 16th, 2010 AT 5:50 PM
Tiny
SATURNTECH9
  • EXPERT
Your welcome -thank you for the prompt response !At battery cable voltage is same 12v. The stud the fuse link goes to; are you refering to the wire on the back of the alternator with the boot cover? If so thats also 12v. (Same when engine is off) I was unable to check the brown & white wires tonight as I put evrything back together( I dont have a lift or sturdy jack so I tested through the wheel well )but the alt is spinning and the tension on the belt is good. Shouldn't I be seeing a voltage increase to about 14v at the alternator if it was charging or would that only show at the battery? When I remove the neg from the battery while idling she dies.[/Quote:7d247d84fb]Yes the wire from the starter to the alternator with boot. With it running that fuse link should have close to 14 volts that is correct. You should also have power to that brown and white wire to the alternator with the key in the run position. If you have all that it should be charging. So let me know what you find.
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Friday, July 16th, 2010 AT 6:09 PM
Tiny
SHAGGYBOB2KK
  • MEMBER
The voltage while the engineis running is only 12v at the alternator stud from the starter/fuse link while grounding the volt meter to the chasis. Have I confirmed that theres no charge/output from the alternator if this should be about 14v -? Without testing the other two wires is safe to say I should replace the alt. Or will testing the other two show other possible problems? (Its under warranty-just my labor lol)? I know with any car electrical issue there can always be the possibilty of another underlying issue that won't show itself until after you've replaced something within the system- just looking for a strong possible culprit, btw the battery indicator light is very dim and flickers slightly while enigine is running- all the other indicator lights are at regular brigtness and steady during the immediate startup and go out like usual a few seconds after strartup. Thanx for all your help !
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Friday, July 16th, 2010 AT 6:27 PM
Tiny
SATURNTECH9
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Your alternator isn't charging if you have 12 volt's at the battery with the car running. If you have battery voltage to the alternator stud then we know the fuse able link is good. If we test to make sure the brown and white wire has power to the alternator with the key on engine off then we know it's a bad alternator.I would just hate to see you take out the alternator and have it be no power to that brown wire. Your going to be there anyways if you replace the alternator. Let me know what you find.
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Friday, July 16th, 2010 AT 7:12 PM
Tiny
SHAGGYBOB2K
  • MEMBER
12v at the brown and white wire while engine off and key in run position, looks like I'm replacing the alternator again. Is it worth paying xtra for a new one as opposed to a refurbished one or are the odds of hittin a bad one about the same?
My batterry indicator light on the dash looks as it may have burned out as it doesn't come on at all, even in keyed run, that would explain the flickering yesterday. I think thats a another issue. Car is 16 years old, bulbs burn out eventually.
Would you believe that the original factory alternator was still in the car with the saturn stamp on it dated 1993 when I replaced it the first time !
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Saturday, July 17th, 2010 AT 10:20 PM
Tiny
SATURNTECH9
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Yeah looks like your going to be changing it out again.As far as new compared to rebuilt i would just stick with the rebuilt where did you get your alternator from?You did very well with your first alternator i used to replace them all the time under warranty when the cars were still under warranty they were a piece of junk till saturn came out with there rebuilt ones and they were better then the new one's lol.They even had a better warranty the new one's that we sold had a 12,000 mile or 12 month warranty and the rebuilt one's were 3 year or 36,000 mile warranty if we installed them at the saturn dealer.I posted the trouble tree for battery light inop for you.


http://www.2carpros.com/forum/automotive_pictures/416332_1994_sl2_battery_light_inop_1.jpg

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Sunday, July 18th, 2010 AT 12:29 AM
Tiny
SHAGGYBOB2KK
  • MEMBER
Thanx for the battery light tree. I replaced the alternator and everything is back to normal. Battery indicator light now works in the key run position/ engine off and the indicator light stays off while engine is running, I got 13.5-14v at the battery with engine running immediately after replacing alternator. Auto-Zone tested the old alternator and it passed, but could not provide any specifics on output.
They replaced it under the warranty anyways so it worked out.
This is such a great forum and you guys have been a great help in tracing this problem down.
I will definitely be back to your site !
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Monday, July 19th, 2010 AT 8:17 PM
Tiny
SATURNTECH9
  • EXPERT
Glad you got everything working again and that you enjoy our site that's what we like to hear. Thanks again for the donation and thank you for using 2carpros.
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Monday, July 19th, 2010 AT 9:10 PM

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