Alternator Question
Thread Starter
Heel & Toe
Joined: Jan 2018
Posts: 15
Likes: 1
From: Mississippi
Alternator Question
I have a 69 big block where the current alternator can’t keep up when the lights and wipers are on. So I’m going to replace it. I’m going to add electric fans and vintage air one day, so looking for a recommendation as to what amp one to get. Thanks for the feedback
Burning Brakes
Joined: Mar 2013
Posts: 750
Likes: 180
From: Springfield Missouri
I would be looking at something like this:
https://www.summitracing.com/parts/p...ette/year/1976
It says for 76 but will fit all Gen I small blocks and big blocks
https://www.summitracing.com/parts/p...ette/year/1976
It says for 76 but will fit all Gen I small blocks and big blocks
Last edited by ntfday; May 25, 2021 at 09:23 PM.
Safety Car
Joined: Apr 2015
Posts: 4,888
Likes: 202
From: Jackson MS
I have a Powermaster 140A in my '77.
It runs the electric fan, Vintage Air, EFI, electric fuel pump, headlights, wipers, and stereo without breaking a sweat.
If you're around this weekend, I'll show it to you.
It runs the electric fan, Vintage Air, EFI, electric fuel pump, headlights, wipers, and stereo without breaking a sweat.
If you're around this weekend, I'll show it to you.
Le Mans Master
Joined: Jan 2001
Posts: 6,742
Likes: 1,384
Don't mess around with upgraded 12SI's..... just got for a 140-amp CS-144...they're a dime a dozen nowadays. There are more modern alternators nowadays but for you purposes it ought to do the trick. Hell, I got mine for 22 bucks at a boneyard about 15 years ago just to see if I could make it fit (68 SBC), it did, and then it even tested sat! I paid more for the 12si to CS-144 adapter cable and new belt than I did for the alternator.
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Race Director
Joined: Jul 2015
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From: SW Florida.
and was probably rebuilt at least once or flat out replaced and rebuilders never cared what the case said and put whatever stator and rotor they had that worked well enough to sell... the original type 10si can be upgraded to 100 amps. but really only if one wanted original appearance under the hood.
Last edited by derekderek; May 26, 2021 at 07:48 AM.
Is my vette stock?? HAHA
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My 68 had the external voltage regulator, not sure if your 69 does. If it does there is a cheap plug and play adapter to eliminate the external voltage regulator so you can switch to a one wire or 3 use a new 3 wire 10 or 12 SI. i have a new 12SI 120amp. I ran a 8 gauge wire to the starter lug to handle the extra amps. If you do that you can just leave the old wire off the alternator but attached to everything else. Its an easy upgrade. Not sure how much a air conditioner is going t need. YOu can find the correct color voltage meters to replace the amp meter pretty easy as wwell
Le Mans Master
Joined: Jan 2001
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Is my vette stock?? HAHA
Joined: Oct 2015
Posts: 20,212
Likes: 9,352
From: Im not allowed to tell you
2020 C3 of the Year Finalist - Modified
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
But it has been a constant issue on this forum that increasing the amperage of the alternator always ruins the amp gauge
Race Director
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Cruise-In VIII Veteran
I'm thinking not always. I have a slightly newer car with the volt gauge. Which I prefer. However I have read on here there is a proper way to wire in the new higher output alternator so as not to burn out the amp meter.