I assume you are referring to the common Delco 10SI or 12 SI alternators. Connect the alternator's large output stud to the ammeter. Make a jumper wire to connect the little terminal on the side of the alternator, marked "2" over to the large output stud. This is the voltage sensing lead. Connect the #1 terminal to a source of power that is switched on and off with the ignition switch. In this line, you must have a diode (1N5008 works great, end with white and towards the #1 terminal), or an "idiot light" with a #194 bulb (or equivalent). If you do not use a diode or light bulb in the "excite" line to the #1 terminal, current can "backfeed" from the alternator into the ignition circuit, causing the engine to keep running when the ignition switch is shut "off". (An oil pressure switch, or a resistor can also be used, but the diode or the "idiot light" are probably the easiest to obtain, and the cheapest ways to do this, and work well.) BobM, over on the Farmall board, grciously makes his diagrams available. You should be able to find a diagram close to what you need. Here's the link:
|