So I've just returned the engine to my 1971 914 along with a complete D-Jet do-over. New vacuum lines, new injectors, new fuel lines, new cold start injector, newly painted intake thorax, new sensors all the way around, a new-to-me MPS, rebuilt alternator, and lovely Bowlsby wiring harnesses, replaced AAR, new Engman fuse panel, new battery, new battery cables, new regulator, new relays, and a rebuilt stock alternator.

My issue: when I start the car it cranks right up but the generator light on the dash stays on solid. Wipers, turn signals, lights, everything else works just fine.

Putting a voltmeter across the battery, it sits at 12.8 volts when the car is at idle, and it ramps up to 13.8 volts when I pull on the throttle. So it seems like the alternator is doing its job. I haven't been able to drive the car enough to know if the battery is draining or not.

On the advice I received at Pelican during the 914w o r l d outage, I was instructed to pull the combination gauge and check the voltages on either side of the generator light. The side with the red and white wires shows 12.8 volts at idle. The blue wire showed zero but the connector was corroded. I kroiled and filed down the connection until it gleamed. Now it shows seven volts.

I also (probably mistakenly) looked at the wiring diagram to see where this blue wire goes. The diagram says this is supposed to be a blue wire to pin #2 on the 14-pin connector on the relay board. Or, I could be reading the diagram wrong. Either way, there is no continuity.

Confused.

Okay. More info. I do indeed have continuity from pin #2 on the relay board connector to the blue wire on the gauge.

I measured seven volts earlier when the idle was higher. Now that the idle has stabilized, I'm getting two volts. Ultimately the blue wire connects right along the regulator and then to the three-pole connector for the alternator. At the ride wire, I also get two volts.

I don't really understand why I'm getting two volts here at the connector, but a solid 13.8 at the battery.

Still confused.

The Blue wire goes to pin #2 on the relay board then to the D+ of the voltage regulator and also to the D+ RED wire to the generator. This is the exciter voltage
to start the generator to charge. When you turn on your key the GEN lamp should light, then go off after starting the engine showing the generator is charging. One side of the Gen lamp is connected switch 12 volts the other side goes to the generator when the circuit is work it connect 12- 14 volts on the other side of the Gen lamp (goes out).
Hope this helps you.

Yes, I get the idea. Its only just penetrated my skull.

I ran the alternator tests mentioned in the Pelican tech article and it pretty much confirms that its a bad alternator, even though it was just rebuilt.

Is this an alternator that you had rebuilt? or a rebuilt from flaps?

It was my original alternator that I had rebuilt by a local Bosch dealer.