9 hours ago, Captain Obvious said:

You're kidding.

How fast does your drill go???

Not fast enough. The alternator is spinning better this morning than it did yesterday. Perhaps with no load, it was the field providing the resistance to movement. Anyway, I'll move to some in situ experiments and check the P terminal on the 240Z's alternator.

On 2/28/2022 at 3:19 PM, Dave WM said:

indeed how is the voltage at idle when fully loaded with demand. I have stock setup including no extra items that increase current draw over the OE needs That being said I do go into a slight discharge mode when idle is at 800 rpm and all electrical is on (head lights, fan, AC clutch, blinkers, wipers) That being said its only at idle, as soon as I get to about 1.1k rpm I am in charge mode (I have an ammeter not a volt meter on my 75). My work around was to bump up the idle when the AC is on to about 1.1k rpm. This keeps me in charge most of time when sitting still in traffic as the AC comes on a lot here in Florida, and the fan draw is generally what puts it into discharge mode. 

I had a few minutes to spend in the garage this evening, so I ran a quick load test on the alternator. With the headlights on and fan on HIGH, voltage went from about 14.4 down to 14.0. It does have an electric fuel pump and GM ECU for the fuel injection, so the load would be comparable to a 280Z at idle.

The real test will be for me to take it on a drive. The old VR/alternator would start out fine, but the voltage would decay as the trip went on, to the point that it was around 12.8 on the voltmeter at idle...No charging, but no draining.