Alternator Replacement

[ChrisGA]

Need advice,

I have been told in the past that if you remove the positive battery cable while the car is running and after you remove the cable the car quits running, then the alternator must be bad. My battery went dead the other day and the car has been not running well (starving for power). Does anyone know if a 1971 corvette alternator (for part numbers) would be the same as for my 71 Avanti. No one shows the Avanti in their systems.

[Gunslinger]

I've heard the same thing but don't know if it's true...whether for all alternator equipped cars, for some or for any at all. Make sure you have a good battery and then have the whole charging system tested before deciding it's the alternator that's the problem.

Does your car have an external voltage regulator or an internally regulated unit? The engines that Avanti Motors installed sometimes ran about a year behind what GM was installing in their own cars. The 350 engine went in Chevy cars in 1969...it didn't appear in Avanti production until 1970. My '70 was equipped with an external voltage regulator when GM converted to internally regulated units in '69. Avanti Motors would make purchases of engines once or twice a year for quantity discounts, so it's easy to understand why the equipment could be a year old before being installed in a car.

An alternator application for a '71 Corvette MAY be the same, but you really need to get the numbers off your current alternator and have it looked up for specs. You can always have your alternator rebuilt and you'll know it's OK and it will fit fine. You can also buy a new replacement from sources like Summit Racing and Jegs.

[ernier]

That's not a test of the alternator.

Since you would probably need to hand your alternator in as a core why not just take it off and have the parts store test it and replace it if necessary.

Better yet put a volt meter on the battery with the car off and then compare numbers with the car running. Battery with car off should be over 13 V. A proper charging sysytem will add about 1.5V to battery voltage. So if you have a weak battery say just 12 volts when the car is running you should see around 13.5V.

ErnieR

[p schmidt]

I went with a chrome one wire alt.from jegs (only need one wire to hook it up!)

[ChrisGA]

Well, not only was the alternator bad, but the regulator was also. I have replaced the alternator and should have the regular installed within the next few days. The regulator the part store gave me was made just like the original but not as tall. Had the exact same hookups but is for a 66 Pontiac. As soon as I showed the original, the part guy knew what it needed and told me it had the same specs. If anyone needs part numbers for the alternator (NAPA) or the regulator, just let me know.