This scematic is the best I could find. It shows it but you have to hunt.
Follow the curcuit from the #1 terminal on the alternator and it will lead to the light then to the ign1 terminal.
It is my understanding if you have the light you don't need the diode. The resistance of the light serves the same purpose. Don't ask me how. I just know I have the light on my externally regulated alternator on my yard dog and have no problems.
