[RSBob]

So there is no confusion about cars, this is about my 914-6 with a 3.0. When originally had the car converted to a 3.0 from a 2.0, I installed an aftermarket combo gauge which provides Volts, oil Temp, oil Pressure and Fuel. All the “bulbs” including idiot lights are LED <- key point. When starting, the red G (alternator light) would come on as expected, but would not go out until I hit 3000 RPM. Below 3000 the volts would read 12. When I hit 3000 then the volts read 14.5 regardless of RPM there after.

So the alternator died last month and was replaced with a new one. Same issue with the G, but now I must hit 4000 RPM for the light to go off and to maintain 14.5 volts. I believe the original resistor is in place on the wire to the alternator LED, but won’t swear to it. I obtained another from Porsche and placed it in-line to the LED and the G spot won’t light up at all, regardless if placed on the hot lead going into the LED or the ground coming out. With the resistor in place the max volts produced are 12.5 regardless of hitting 3000 or 4000 RPM. So I removed it.

My theory is that the LED is not creating the correct resistance to send feedback to the alternator/ voltage regulator to produce the 14.5 until 4000 is hit. For fun I temporarily wired in a higher voltage light (not a gauge light) instead of the LED and the engine wouldn’t turn off even with the key until the bulb was disconnected. If I felt like it, this would be a good place to wire in a kill switch, but I don’t.

Now keep in mind I am an electrical idiot, (and idiot in many other rights) own a volt meter but don’t know how to use it. So my questions are:

1. what is the correct resistance needed to turn off the G light at start up and
2. where exactly do you, and
3. HOW, do you measure it? Is it on the red wire going into the LED or the black wire/ground coming out? Remember this is a non standard gauge.
4. What settings on the Voltmeter to read?
5. Why Is putting the new resistor in-line creating too much resistance thus preventing the alternator from correctly functioning?

When I learn the correct amount of resistance I need from you guys and then can learn to read mine, then I would think it would be a simple matter of subtracting my readings from the correct resistance to buy the correct resistor. That is my best guess as an idiot. Please feel free to correct me.

I don’t have access to a standard gauge.

Until then, HAYULP!