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damien89 | Started the vette (89) today and have low voltage, any help? | ||
Guru
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Hi everyone, its been a while since iv'e posted here. Today i went to start my dad's 89 vette. When it cranked it cranked a bit slow but its because it had been sitting for a month.
After it started i noticed a humming noise coming from the engine but it was really low this noise that i didn't take notice of it as i thought it was my ears playing tricks on me. So i left it idling and went to do something in the other garage, after 5 minutes i go back and again there was a faint humming noise, i looked at the engine bay but i couldn't find were it was coming from. Then i went to turn it off and saw that the dash was really dim, so i checked the voltage and found it was 9.6v! So i turned the engine off. Then tried to restart it and the starter just clicked without turning. I hooked up the battery charger and left it for an hour. After that i started the engine but the voltage was 11.1v and it was getting low 10.7, 10.5 etc after 2-5mins. I checked the battery voltage with a multimeter and it was almost the same as the gauge on the dash. How can i check the alternator without removing it from the car to see if its charging or not? Could the humming be related? Maybe something in the alternator broke? |
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Posted on: 2014/5/31 18:59
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bogus | Re: Started the vette (89) today and have low voltage, any help? | ||
Grand Imperial Pooh-Bah
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Welcome back!! The alternator is dead... long live the alternator. When they start humming, you can be assured that the voltage regulator, the diodes or both have died. One more trick, restart the engine, put a long screwdriver on the chassis of the alternator and put your ear to the handle. Listen... is it really loud? The answer will be yes and that goes along with... The deduction is simple... noise? check. Low voltage? Check. Buy new alternator, or, get yours rebuilt by a good local shop (they still exist!). |
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Posted on: 2014/5/31 19:11
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The single biggest problem with communication is the illusion that it has taken place. - George Bernard Shaw Education is the best tool to overcome irrational fear. - me |
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damien89 | Re: Started the vette (89) today and have low voltage, any help? | ||
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Quote:
Hi bogus! Thanks for the reply, tonight i will let the charger charge the battery and check it tomorrow morning, if its dead which probably it is i will remove it and take it to a good electrical shop to see if it can be repaired. |
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Posted on: 2014/5/31 19:48
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bogus | Re: Started the vette (89) today and have low voltage, any help? | ||
Grand Imperial Pooh-Bah
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99% of the time, an alternator can be rebuilt. The only problem is if the windings on the armature get torn up some way.
Brushes, diodes, regulators... all replaceable, same with bearings. |
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Posted on: 2014/5/31 21:10
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The single biggest problem with communication is the illusion that it has taken place. - George Bernard Shaw Education is the best tool to overcome irrational fear. - me |
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Matatk | Re: Started the vette (89) today and have low voltage, any help? | ||
Webmaster
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I would agree with Andy. You can check it at home, but an electric shop will test it free. The C4s are notorious for eating up alternators.
http://easyautodiagnostics.com/altern ... or_diagnostic_tests_1.php |
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Posted on: 2014/6/1 13:04
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2002 EBM convertible, Magnusson supercharger, cam, headers, etc. 1989 Corvette...RIP |
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joeld | Re: Started the vette (89) today and have low voltage, any help? | ||
Guru
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Also, charge the battery fully before the engine is started and ran with the replacement alternator. A alternator is not designed to charge a battery, only to maintain it while running.
Joel |
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Posted on: 2014/6/1 14:50
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1989 Coupe,L98 automatic |
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bogus | Re: Started the vette (89) today and have low voltage, any help? | ||
Grand Imperial Pooh-Bah
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Joel is right... But to put a finer point on his comment, the alternator is designed to recharge a battery after losing 1% during start-up... then running the car... that's it...
The battery is outside the the loop, so to speak, of regular operations. |
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Posted on: 2014/6/2 15:03
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The single biggest problem with communication is the illusion that it has taken place. - George Bernard Shaw Education is the best tool to overcome irrational fear. - me |
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damien89 | Re: Started the vette (89) today and have low voltage, any help? | ||
Guru
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Hi guys an update about the no charging issue.
I took the alternator to an auto electrician and he replace the rectifier and both bearings, i installed the alt back all was well for just 10 miles as the battery light came on and the voltage dropped to 11v. Checked the alternator again with the multimeter and with the engine running i was just seeing .6v. I removed the alternator again and took it to the same elctrician and later that day he called me to tell me that the regulator needed replacing. So he replaced it and i installed it back and for now everything is ok. |
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Posted on: 2014/6/22 16:43
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Matatk | Re: Started the vette (89) today and have low voltage, any help? | ||
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Glad it is back up and running!
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Posted on: 2014/6/22 19:15
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2002 EBM convertible, Magnusson supercharger, cam, headers, etc. 1989 Corvette...RIP |
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