On the 2003 Buick Century, when the blower motor only works intermittently, this is going to be either a poor connection at either the Blower Motor Resistor or a failing Blower Motor itself. First, remove the passenger’s side insulator panel (the panel right above where the passenger’s feet would be) to gain access. Then, inspect the electrical connectors to the Blower Motor Resistor and motor looking for any loose, broken or damaged wires. If the visual inspection checks ok, then you should test for power to the blower motor the next time the blower is not working. Purple = ( + ) / Black = ( – ). If power is present, then the Blower Motor will need to be replaced. If power is not present, test for power at the Resistor. Orange = ( + ) / Black = ( – ) if power is present here, the resistor will need to be replaced. If no power to the resistor, then the problem lines in the circuit between the control panel and the blower/resistor or internal of the control panel itself.
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