Blower Motor: Testing and Inspection

A/C BLOWER MOTOR CURRENT DRAW TEST
The current draw test will determine if the blower motor is operating properly. Connect a Rotunda 73 Digital Multimeter 105-R0051 or equivalent between battery ground and the negative lead of the blower motor. The measured current draw represents A/C blower motor operation in the high-speed setting. If the blower motor is operating properly, the current draw readings will be within specification.

In all electrical circuits, continuity must exist from the source of power battery positive voltage (B+) to the unit where the power is used and back up to the source of power ground. A check at each connection in a circuit, starting at the battery, will locate an open circuit or will show that the circuit is complete.

Rotunda 73 Digital Multimeter 105-R0051 or equivalent connected at any two points of a circuit with the power removed from the circuit, will show if the circuit between the two connections is open or complete.

If the meter does not move or has a slight movement (high resistance), the circuit may have a poor connection or broken wire.

If the ohmmeter movement is great or full (low resistance), the circuit is complete.