I Just worked on one of these a week ago installed new batteries and a couple bad Contactors and spent several hours replacing cables....this truck does have a 12 volt charger and the lift motor runs off 12 volts but the drive motor runs on both 12 and 24 volts(high speed)....first speed is 12 volts running thru a resistor then to the drive motor...second speed is 12 volts bypassing the resistor and high speed is when the two left most Contactors (b & c) close and put the batteries in series to give the motor 24 volts....the middle Contactor(A) should have a switch at the top of it that activates the coil for the C Contactor.....