Alternator

The DOHC alternator is much skinnier... but there are probably other electrical reasons it won't work.
 
Anyone know what the alternator output should be at idle? Mine was just tested by Advance Auto, and they said it should be at 15 mine was at 13.5.
My almost 3 yr old battery had to be replaced.
 
turn_on68 said:
Anyone know what the alternator output should be at idle? Mine was just tested by Advance Auto, and they said it should be at 15 mine was at 13.5.
My almost 3 yr old battery had to be replaced.
Click to expand...

Did they test it with the new battery or old battery? And did they spin it up on the bench tester or in the car?

If it was with the new battery and you were outputting at 13.5, it's borderline minimum. 15 is actually too high, you want right around 14.1-14.2. If it was 13.5 on the dead battery, have them check it with the new one in there and make sure it's higher. Otherwise, you're likely to kill another battery over time.
 
luxuryrules said:
Did they test it with the new battery or old battery? And did they spin it up on the bench tester or in the car?

If it was with the new battery and you were outputting at 13.5, it's borderline minimum. 15 is actually too high, you want right around 14.1-14.2. If it was 13.5 on the dead battery, have them check it with the new one in there and make sure it's higher. Otherwise, you're likely to kill another battery over time.
Click to expand...

It was with the new battery in the car alternator on the car and at idle. Wouldn't the amps go up at a faster rpm?
 
turn_on68 said:
Anyone know what the alternator output should be at idle? Mine was just tested by Advance Auto, and they said it should be at 15 mine was at 13.5.
My almost 3 yr old battery had to be replaced.
Click to expand...
15!? Not likely.

13.5 is normal.

Even on an ice cold day, I'd be very surprised to see those voltages. 14.6 (or so) while the engine is warming up.

Once the engine is hot, and the radiator fan has been blowing hot air on that alternator, I wouldn't count on seeing anything higher than 13.8 if you're lucky.
 
15 is high maybe your voltage regulator went bad like mine did.
 
Abbens said:
15 is high maybe your voltage regulator went bad like mine did.
Click to expand...

No I am not getting 15 only 13.5, so it sounds like my alternator is okay then at 13.5. I have always assumed a battery would fail in 3 years, so all is okay then. I do not need to replace the alternator.:)
 
turn_on68 said:
It was with the new battery in the car alternator on the car and at idle. Wouldn't the amps go up at a faster rpm?
Click to expand...

Not with a functioning voltage regulator.

If you want to be safe, yank the alternator and carry it down, have them throw it on their bench tester. It's much more accurate than the in-car tester. Your need to do so is not urgent, but it should be a fun weekend project.
 
With engine RPM at 2,000 the alt. should put out a min of 87 AMPS with lights on etc, anything less is new alt time.

Voltage has to be atleast .5 volts over base voltage while doing the above.
 
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