I have a 2002 Pontiac Montana and the blower motor works on all speeds except high. Is most probable problem the blower motor resistor? As an aside, the same time this happened my headlights failed to be bright any longer, whether on high beams or low beams, could this be a connected problem?
I have checked all fuses and all are fine. Have checked the battery and alternator, all
voltages are reading properly.