Hey Bob Melville?

Single wire alternators are found a lot in marine applications - probably also in other stuff like your forklift. And hot rodders seem to like 'em because they're simple to wire up. You can convert a regular 3 wire alternator to a single wire by swapping in a special single wire regulator.

First of all, what year is this truck? The Delco alternators that were built after the 10SI was discontinued use internal sensing. Simply put, they run a low-value resistor from the BAT terminal to the sensing circuit. You can still use external sensing if you wish. Even the 10SI can be modified to use internal sensing. This is sensing only - excitation is another story. You can find "single wire" alternators that also use internal excitation. These are usually modified 10SI alternators. I usually preach to use 3-wire configurations for two reasons: 1) They are more readily available and less expensive. 2) You do not need as much RPM the start the alternator charging. This can be a significant issue when you are driving an alternator with a low RPM engine - as found on a tractor.

I might mention that while 14.6 volts is satisfactory, it is a bit high. Something around 14.0 volts is more desireable. With a 14.6 charging voltage, you will need to watch the battery a bit more closely. The battery will tend to use more water.