I just installed a rebuilt alt. from Vick's. Now it has a whirring or whistling sound with the rev of the engine. I never had this before. I am also noticing I am only averaging about 12.5 volts from the alternator. Should they not be about 14?
Help?
Keith
Alternator Question?!?
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baltobernie
- Patron 2020
- Posts: 3466
- Joined: Sun Nov 25, 2007 6:00 pm
- Your car is a: 1973 Spider [sold]
- Location: Baltimore, MD
Re: Alternator Question?!?
(At least) three alternators used on Spiders: 42A Marelli, 55A Bosch, 65A Bosch. External and integrated regulators. What setup do you have? Photos if you don't have model numbers.
General Info: Did they package anything with the unit? Most places give you a printout of the alternator's bench tested numbers. Also warnings about how and where to place your lever to tension the belt (i.e. never on the rear half of the unit). Sound like a bearing whine? Belt too tight? You want 1/2 to 1 inch of total movement midway between the engine and alternator pullies. Output is a function of alternator and regulator working together properly. With a fully-charged battery and no load, voltage at the alternator will be equal to battery voltage, approx. 12.8 V. With engine running, turn on all electrical accessories; measure voltage. Turn all accessories off; measure at the same location again. Tell us what you get.
General Info: Did they package anything with the unit? Most places give you a printout of the alternator's bench tested numbers. Also warnings about how and where to place your lever to tension the belt (i.e. never on the rear half of the unit). Sound like a bearing whine? Belt too tight? You want 1/2 to 1 inch of total movement midway between the engine and alternator pullies. Output is a function of alternator and regulator working together properly. With a fully-charged battery and no load, voltage at the alternator will be equal to battery voltage, approx. 12.8 V. With engine running, turn on all electrical accessories; measure voltage. Turn all accessories off; measure at the same location again. Tell us what you get.