after reading all this i have forgoten all that i have ever learned, (about electricity) thik about the voltage as pressure pushing the ampers through the wires to turn the motor. Your switch puts more resistance in the wire, need more pressure to push the amps. don't have more presure, 6 or 12 volts steady. so not as many electrons (amps) go to the motor. the resitance slowing the amps creates heat. Engergy can only be changed, not destroyed. volts are only pressure. amps are flow.
