The Stovebolt Site Forums The Shop Area The Electrical Bay rewiring my 46 12 volt 1/2t. Is the alt diode neccessary?

I've got the modern EZ wire kit and a modern 3 wire alt. I'm wondering:
1. do I need to install a diode from the number 1 terminal on the back of the alt?

2. If I need to install a diode where do I connect this wire from the number one terminal on the alt to? Does it go to the ignition switch? If so which contact, start or batt or acc or ign?
Or does it go to the starter?

Rick.......

The diode is usually necessary to prevent current feedback to the ignition system if you're not using an idiot light. The engine will run on if enough current feeds back from the alternator to keep the coil firing. The #2 wire can be connected directly to the big battery terminal at the back of the alternator housing, but the #1 wire needs to have switched voltage either from the coil input or the ignition switch. A 100 ohm 10 watt resistor works about as well as a diode.
Jerry

Jerry,
Thanks for the reply. That's sounds exactly what I have now. The number 1 wire goes through a diode then splits with one wire going to the pos side of the coil and the second wire goes to the switched side of the ignition switch. If this sounds ok I will go back the same way with the new wires.

Thanks.

That will work, but GM chose to make the #2 terminal hot all the time in the OEM wiring harness- - - -no switching whatsoever for some reason. Going to both ign. switch and coil with the same circuit, then to the #1 terminal makes no sense at all. Use one or the other, not both.
Jerry