To-20 12v conversion problem

Here is a rear view of my tractor. On the dash below and left of the ammeter you can see the Side Marker Lamp alternator "idiot" light. The purpose of the light in the conversion is to prevent the backflow of electricity in the excite circuit. If the light bulb is omitted from the conversion, the engine will continue to run even after the key is turned off due to the backflow of electricity from the P1 terminal on the alternator to the "ACCESSORY" post on the Terminal Block, and then out to the coil. For best results, use a lamp that utilizes the #194 (or #193) bulb. Initially, I used a small "indicator light" that installed through a single hole in the dashboard and had 2 spade connectors on the back, and was much smaller than the Side Marker Lamp. The drawback was that I had to rev the engine to nearly full throttle to get the alternator to excite and begin charging. I wasn't too thrilled about doing that each time I started the engine, so I went out and got the correct parts. If you desire, a 1 amp 50 volt diode can also be used in lieu of the light bulb.