bad alternator???
Thread Starter
Intermediate
Joined: Aug 2002
Posts: 30
Likes: 0
From: Carlisle PA
bad alternator???
Just recentlyI started having my 85 coupe start "roughly". When I'm driving the dash says the battery charge is around 14 volts. When I turn it off and then start it up later, it starts rough and the voltage is onlyy 8-10. It starts but it's not normal. One of these times I am afraid it won't start. I just put a new battery in it a few days ago but that didn't solve the problem. Someone told me it might be the alternator. Anyone care to comment or give some advice?
Thanks for you help in advance
Thanks for you help in advance
Drifting
Joined: Aug 2002
Posts: 1,339
Likes: 0
From: Hampton Georgia
Re: bad alternator??? (vettelover1985)
Im not for sure what the problem is but I do know that those alternators are a common problem .If you buy one ,buy one with a lifetime warranty.Ive collected on that warranty twice. :yesnod:
Burning Brakes
Joined: Oct 2000
Posts: 863
Likes: 0
From: Portsmouth,Va USA
Re: bad alternator??? (vettelover1985)
I started getting erratic readings before my alternator failed..
Your car needs the proper vopltage to run properly..
I replaced my alternator. NO more problems..
good luck..
Your car needs the proper vopltage to run properly..
I replaced my alternator. NO more problems..
good luck..
Team Owner
Joined: Jul 2002
Posts: 22,267
Likes: 15
From: The light that never warms.
St. Jude Donor '12
Re: bad alternator??? (Rick Williams)
If you replace your alternator, I would suggest dumping the old SI and stepping up to a CS unit. That is the type that Chevy went to in '86. They are smaller, run cooler, put out cleaner juice, and put out more amps at idle than the SI. The SI in '85 was a huge 120 amp monster that was on its' last legs.
If you are interested, I have done this swap. Delco makes an adapter specifically for this. I can email you the part numbers for a CS144 and the adapter.
If you are interested, I have done this swap. Delco makes an adapter specifically for this. I can email you the part numbers for a CS144 and the adapter.
Team Owner
Joined: Jul 2002
Posts: 22,267
Likes: 15
From: The light that never warms.
St. Jude Donor '12
Re: bad alternator??? (paulie)
Sure.
It's a really good upgrade for both '84 and '85. Those alternators are real POS. I rebuilt mine twice before I saw this article in Chevy High Performance about the upgrade to a CS144.
The only way to go. :D
It's a really good upgrade for both '84 and '85. Those alternators are real POS. I rebuilt mine twice before I saw this article in Chevy High Performance about the upgrade to a CS144.
The only way to go. :D
Team Owner
Joined: Mar 2001
Posts: 54,124
Likes: 30
From: Cincinnati, Oh USA
Re: bad alternator??? (vettelover1985)
If the alternator isn't charging , the red battery light will come on in your dash. During cranking, the alternator isn't putting out anything as it is turning too slow and if you have slow cranking and low voltage, then you have either a discharged battery, or poor battery cable connections. Measure the voltage across the battery when cranking. It should not fall below 9.0 volts . If it does and since you have a new battery, charge it up and remove the battery cables (Neg first) and clean the cable lugs and the battery posts and replace (Neg last). The starter requires 100+ amps when cranking and it needs very low connection resistance to the battery. You want your battery connections to be just like your lover, bright and tight. :D
Instructor
Joined: Jul 2000
Posts: 203
Likes: 3
From: Galesburg IL
Re: bad alternator??? (lite blue)
If you replace your alternator, I would suggest dumping the old SI and stepping up to a CS unit. That is the type that Chevy went to in '86. They are smaller, run cooler, put out cleaner juice, and put out more amps at idle than the SI. The SI in '85 was a huge 120 amp monster that was on its' last legs.
If you are interested, I have done this swap. Delco makes an adapter specifically for this. I can email you the part numbers for a CS144 and the adapter.
If you are interested, I have done this swap. Delco makes an adapter specifically for this. I can email you the part numbers for a CS144 and the adapter.
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Drifting
Joined: Aug 2001
Posts: 1,407
Likes: 0
From: Houston TX
Re: bad alternator??? (steveb)
Be sure to check your battery cables. Sometimes they look good on the outside but on the inside they are bad. Especially on older cars. You can have your alternator checked quickly at Pep Boys for $10-15. Not sure on the cost but they will run a print out on your amps. Good luck, I just replaced mine.
poopie, I have just about replaced everything..she's a keeper for sure now.
:seeya
poopie, I have just about replaced everything..she's a keeper for sure now.
:seeya
