1965 327 alternator options

Arthur Gould Rebuilders       |       789 Wachusett St., Holden, MA 01520      |      508-210-0891

Air conditioning cars received a 40 amp alternator over the standard 35 amp alternator.

The A/C blower motor draws the same amount of current as the heater blower motor and the A/C compressor clutch only draws 2 amps when it is engaged. In other words, A/C on max only uses 2 amps more than the heater on max. That is why the alternator on A/C cars I only 5 amps higher in rating. That is all you need.

A 55 amp alternator was optional as a heavy duty item.

All three alternators do not charge well at idle speeds because the 327 idles so slow. The headlights will dim at idle, especially if the blower motor is running too. It won't cause excessive discharging of the batter unless you sit there and idle for a very long time. Like...hours. It's different than we are used to on newer cars but it's nothing to be worried about. It's still charging at idle better than if it had a generator and cars ran fine with generators for many decades.

Re the regulator: Just sharing a bit of personal trauma.  I've got the 40 Amp (it's actually a little less than that) setup in a 67 Ambo with 343.  I too had a big problem with the regulator.  It turns out that the regulator ground is through the wiring harness and not via the case.  Yup, you can see that in the wiring diagram.  The reason it's worth mentioning is that the press-on terminal for the ground at the back of the alternator for the factory harness gets tired.  I'm not completely sure why but if the regulator is not grounded correctly for about a nanosecond (don't really know how long but darn short), then it fries.  I was checking all the connections, replacing regulators, but during actual driving there was the occasional vibration that seemed to caused the ground to open.  I cut off the end of the harness at the alternator, crimped on eye-type fittings, securely tightened them including a star lock washer and no further regulator problems.