Alternator amps
Thread Starter
Heel & Toe
Joined: Jun 2008
Posts: 22
Likes: 0
Alternator amps
My car died last night on hwy 401 in Toronto...not fun. My guess is that it's the alternator. I figure this is a job I can take on myself, but now need to understand what I do & do not need. I see alternators ranging from 42 to 100Amp. There are also a number of brands to choose from and I'd be interested in hearing of any recommendations. For example, here is a link from Mid America that shows several different options:
http://www.mamotorworks.com/corvette?frame=4.9133
I simply don't know enough to make an informed decision so any help would be greatly appreciated.
Thanks all.
http://www.mamotorworks.com/corvette?frame=4.9133
I simply don't know enough to make an informed decision so any help would be greatly appreciated.
Thanks all.
Melting Slicks
Joined: Jul 2005
Posts: 2,545
Likes: 3
From: 406ci SB, AFR 180 Heads - 490 HP @5,600 RPM 529 lb-ft @ 4,100 RPM
Go to any parts store (CTC -Napa-Part Source/ GM Dealer), tell them the year/ engine/ position of your plug. (example my plug was at 6 oclock I believe) and order a 100 amp and you will be ok. Plug position is important and you want one for a 3 wire plug. Some come 3 and 1 wire and they will work also, stay away from only 1 wire plug hookup.
Last edited by Glass Act; Apr 13, 2009 at 11:16 AM.
Race Director
Joined: Jul 2001
Posts: 15,892
Likes: 42
Why 'just guess' at what broke? Find out for sure what is wrong. If it is the alternator, any local parts house will have a correct replacement. Even Canadian Tire.
If the unit you are removing is the original, keep it and do not use it as a trade in core.
You do not need and will not benefit by putting in a bigger or more modern unit.
If the unit you are removing is the original, keep it and do not use it as a trade in core.
You do not need and will not benefit by putting in a bigger or more modern unit.
Thread Starter
Heel & Toe
Joined: Jun 2008
Posts: 22
Likes: 0
Thanks so much for the quick reply. I just went out to take a look at the unit and understand what you meant by plug position. I attached a picture I took, and figure plug position is at about 6o'clock. Upon closer look, I noticed a frayed wire, which I circled in the picture below (hopefully it works).
Kind of changes things...any additional thoughts??
Kind of changes things...any additional thoughts??
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
That is actually not the correct way that yours should be clocked. The plug should be at 11 or 12 oclock. Bubba has been at your alternater
You could reclock it and have it sitting correctly. There are 4 small screws holding the case together. You can remove then and slightly pull the case apart, only 1/8 to 1/4 of and inch apart is needed and reclock the case. The wires should be at the top of the alternater.
You could reclock it and have it sitting correctly. There are 4 small screws holding the case together. You can remove then and slightly pull the case apart, only 1/8 to 1/4 of and inch apart is needed and reclock the case. The wires should be at the top of the alternater.
Last edited by Gordonm; Apr 13, 2009 at 11:13 AM.
Melting Slicks
Joined: Jul 2005
Posts: 2,545
Likes: 3
From: 406ci SB, AFR 180 Heads - 490 HP @5,600 RPM 529 lb-ft @ 4,100 RPM
My 79 I can't truly say, but again the plug wire is in the same position, not that it really matters.
Thread Starter
Heel & Toe
Joined: Jun 2008
Posts: 22
Likes: 0
Thanks so much for the fast responses, it's greatly appreciated.
Ok, so I'd prefer to get a new plug rather than repair this one. As far as proper plug position goes, how much of an issue is this? Do I simply reposition the existing unit? Do I have the wrong unit all together? I'd have to go back into the car's records to see if/when the alternator was ever replaced...will identify the "bubba"!
Ok, so I'd prefer to get a new plug rather than repair this one. As far as proper plug position goes, how much of an issue is this? Do I simply reposition the existing unit? Do I have the wrong unit all together? I'd have to go back into the car's records to see if/when the alternator was ever replaced...will identify the "bubba"!
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Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
Not sure Gordonm, my 72 I have owned since 1974 and my plug is the same as shown, no one has ever worked on the car but me, that alt. is 37 years old and still going strong.
My 79 I can't truly say, but again the plug wire is in the same position, not that it really matters.
My 79 I can't truly say, but again the plug wire is in the same position, not that it really matters.
I know I am right on this one. I researched this a few years ago because this came up I think it was here on the forum. Gm would also not have the back letter casing reading at a 90 degree off. I can see a few degrees depending on belt length but not 90. I just looked in some of my old NCRS books and the pictures show it as the plug being up. Now these are old books and my research is a few years old so if anyone can confirm me wrong I am open to it. You always think you are correct but I usually end up sticking my foot in my mouth.
Looking a ta few more pictures it looks like the plug is clocked with the threaded mounting hole. Depending on options and how the alt. was mounted it could be a little further over when mounted but the plug looks to always clock with the threaded mounting hole.
Last edited by Gordonm; Apr 13, 2009 at 11:58 AM.
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
Thanks so much for the fast responses, it's greatly appreciated.
Ok, so I'd prefer to get a new plug rather than repair this one. As far as proper plug position goes, how much of an issue is this? Do I simply reposition the existing unit? Do I have the wrong unit all together? I'd have to go back into the car's records to see if/when the alternator was ever replaced...will identify the "bubba"!
Ok, so I'd prefer to get a new plug rather than repair this one. As far as proper plug position goes, how much of an issue is this? Do I simply reposition the existing unit? Do I have the wrong unit all together? I'd have to go back into the car's records to see if/when the alternator was ever replaced...will identify the "bubba"!
Melting Slicks
Joined: Sep 2004
Posts: 3,227
Likes: 670
From: Northeast
It appears from the letters that the case is Delco-Remy. If this one goes just have it rebuilt. At that time they can clock it for you and there is no use to buy a new case. (Save your picture)
My alternator from Summit lasted only 7 years and I had it rebuilt. No use spending another $100+
Good luck.
My alternator from Summit lasted only 7 years and I had it rebuilt. No use spending another $100+
Good luck.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
Obviously, your alternator has been working fine; and I would expect that it will continue to work "fine" after you fix the wire in that socket. Remove that socket from the alternator, remove the positive wire from your battery (or turn "off" your battery disconnect if you have one), get a small jeweler's screwdriver and push it into the outer end of the damaged wire/connector in that socket. There is a small detent tab on the metal contact that, when depressed, will allow that connector to be removed from the socket. Take that connector to your local auto parts store and buy a new one (it wouldn't hurt to re-do both connectors, since they are probably pretty worn...but remember which one goes where). Strip the insulation back on the wires a bit and crimp on the new connectors; then slide them back into the plastic housing. Done deal! [for less than $2]
Thread Starter
Heel & Toe
Joined: Jun 2008
Posts: 22
Likes: 0
Thanks again for all the responses. I got the detail off of the alternator:
Delco-Remy
1100-901, 42A
So, it looks to be the original. CT did not have the plug (but did charge my battery for me), but I did find one at NAPA for $3. Once I get some free time to wire it up, I'll be sure to follow up on whether it did the trick or not.
I greatly appreciate all the assistance, everyone. Really great to see all the genuine interest in helping out!
Delco-Remy
1100-901, 42A
So, it looks to be the original. CT did not have the plug (but did charge my battery for me), but I did find one at NAPA for $3. Once I get some free time to wire it up, I'll be sure to follow up on whether it did the trick or not.
I greatly appreciate all the assistance, everyone. Really great to see all the genuine interest in helping out!
Racer
Joined: Nov 2008
Posts: 326
Likes: 0
I did make that mistake buying an alt. from Ecklers. My plug on the new alt. was at 3:00 and the plug on my 81 was at 9:00. I had to loosen a few wires in the harness to get it to reach. I'm gonna by a new plug with wires on it and crimp the wires together and stuff them in the harness so it doesn't look like bubba was there.
Thread Starter
Heel & Toe
Joined: Jun 2008
Posts: 22
Likes: 0
Yeah, the plug I got has two wires already. Think I'll use a butt connector to join the wires and wrap it afterwards to hide it. All the wires there are wrapped anyway. Hopefully that does the trick. Will get around to it on the weekend.
Thread Starter
Heel & Toe
Joined: Jun 2008
Posts: 22
Likes: 0
Well, it's been a busy few weeks, but I finally made the repair. The $3 connector worked! I fired up the car today with no problems. I took it out for a few miles and all went well. Looking under the hood, I could not help but notice the movement the alternator had once the motor had started. I'm just curious how much slack should there be....ie how much "sway" should the alternator have? Is there a rule of thumb on how tight the belt should be?
Thanks again to everyone.
Thanks again to everyone.
Racer
Joined: Feb 2009
Posts: 427
Likes: 49
From: Pgh. Pa.
Rule of thumb grab fan with your hand and try to turn it. If it turns without moving the belt with it, it is too loose. 1100901 front and finned rear alt . Nice and worth a few bucks. If you do have it rebuilt make sure you get the same one back.
Le Mans Master
Joined: Feb 1999
Posts: 8,351
Likes: 75
From: Tampa Bay FL
Thanks so much for the fast responses, it's greatly appreciated.
Ok, so I'd prefer to get a new plug rather than repair this one. As far as proper plug position goes, how much of an issue is this? Do I simply reposition the existing unit? Do I have the wrong unit all together? I'd have to go back into the car's records to see if/when the alternator was ever replaced...will identify the "bubba"!
Ok, so I'd prefer to get a new plug rather than repair this one. As far as proper plug position goes, how much of an issue is this? Do I simply reposition the existing unit? Do I have the wrong unit all together? I'd have to go back into the car's records to see if/when the alternator was ever replaced...will identify the "bubba"!
Fix the $5, 2-wire connector, charge the battery and enjoy the C3!
P.S. I tested my alternator on Tuesday. From my reference literature, a healthy alternator should produce 14 volts at the alternator with the car running (black tester wire on the black wire on the alternator or any grounded chassis component and red tester wire on the red/hot wire that has the rubber cap over it on the rear of the alternator. With the engine off, a healthy battery should produce 12.5 volts (black tester wire on the '-' battery terminal and red test wire on the '+' battery terminal).... Or, you can just take the alternator and battery to the local parts store for testing/peace of mind.
Once you fix the damaged wire and verify all is well with the alternator and battery, you should be good to go!