I offer this as it may help others. My neighbours have a Ford 7710 tractor. The original internally regulated Lucas alternator failed and a new replacement was purchased from New Holland. The replacement is a SPS with little or no installation instructions. It mounts correctly but they couldn't get it to work. The tractor has a temperature compensator under the battery box. They had joined the 2 wires for the compensator together removing it from the circuit. I found that the SPS alternator could be made to work by adding a 1000 ohm resistor in series with the sense lead. I suspect the compensator is a thermistor and that the voltage to the sense lead is less than typical battery voltage. Probably the internal regulator in the SPS alternator is reading the voltage across a resistor network. So when you apply battery voltage to the sense lead it reads it as being high and the regulator shuts down the alternator.
This nonsense is typical in that the wiring diagram tells you nothing usefull and the alternator doesn't come with instructions either.
This nonsense is typical in that the wiring diagram tells you nothing usefull and the alternator doesn't come with instructions either.
