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Old 10-02-2021, 01:50 PM
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abefromen abefromen is offline
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Join Date: Jul 2007
Location: a van down by the river
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Quote:
Originally Posted by george kujanski View Post
The voltage regulator has a built-in temperature compensation, at cold temps it will charge a a higher voltage, hi temps at a lower voltage.

That said, yours seems to be over-compensated (drops too low at higher temps), or you are not getting enuf airflow thru the alt. Check for belt slippage, fan too far away from the front housing, hot air entering the rear housing. An alt gets cooled by sucking air into the rear housing and out the fan.

If you have a one-wire, change to the 3-wire connection that has the voltage sense point at the battery.

If all that is good, I'd say the regulator is over compensated. Case in point, I had a Caddy Northstar in which I replaced the alt with with an AC Delco. Now it performs exactly as you describe......the issue is worse with the Northstar, the exhaust manifold is right next to the rear housing of the alt.

If you can, see if you can get a regulator from a different manufacturer, maybe even and old OEM part. In my case I just left it because the alt is such a b!tch to change...

george
It's the original '77 three wire alt.

Belt is tight and pulley is good.

The regulator and all other internal parts I swapped out are all NOS Delco items bought off ebay, no offshore junk as I didn't want problems but unfortunately I have one although quality parts were used.......but then again new doesn't always mean good. Maybe the regulator was dropped at some point who knows.

Only original parts reused are the stator and rotor that's why I thought either/or may be the issue. I just don't want to swap parts unless bad.

Is there supposed to be heat sink grease on back of the regulator? I don't remember doing it if so.
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