The two small wires coming from the brush holder are connected to a negative-temperature-coefficient thermistor that has a resistance of 15 to 35K ohms at ambient temperature and about 2k ohms at the maximum acceptable temperature of the brush holder.
In an application where there could be a risk of overloading or overheating, these wires should be connected to the controller circuit in such a way that the maximum current will start to be cut back when the thermistor's resistance falls below 4 to 5K ohms and will be low enough to prevent further temperature rise when the resistance has fallen to 2K ohms.
The wires can simply be connected in parallel with the throttle potentiometer if it has a two wire connection, and 0 ohms = stop and 5K ohms = full throttle.
In an application where there could be a risk of overloading or overheating, these wires should be connected to the controller circuit in such a way that the maximum current will start to be cut back when the thermistor's resistance falls below 4 to 5K ohms and will be low enough to prevent further temperature rise when the resistance has fallen to 2K ohms.
The wires can simply be connected in parallel with the throttle potentiometer if it has a two wire connection, and 0 ohms = stop and 5K ohms = full throttle.
