Blower Motor Current Draw Test

Heater Blower Motor Current Draw Test - Schematic:

This in-vehicle test will determine if the blower motor is operating properly.
1. Connect a 0-30 ammeter.
2. Ground the negative side of the blower motor connector with a 10-gauge or larger jumper wire, and measure the motor current draw.
3. If the unit is operating properly, the current draw readings will be:
a. Low 4.5-5.5 amps.
b. Medium Low 7.0-8.0 amps.
c. Medium High 14.0-18.0 amps.
d. High 20.0-25.0 amps.