Blower Motor Testing

With ignition on, check fuses. If fuses are bad, check wiring harness for short circuits. If fuses are okay, check for voltage between heater relay and ground circuit. If there is no voltage, check for broken wire between fuse block and heater relay. If there is voltage, go to next step.
If there is voltage at heater relay, check relay, and replace if necessary. See BLOWER MOTOR RELAY TEST in this article. If relay is okay, disconnect blower motor connector. Set heater switch to either LO, MED or HI.
Check voltage between harness side of connector and vehicle ground. Voltage should be 12 volts. If 12 volts are present, go to next step. If voltage is not present, check for continuity between resistor terminals. See BLOWER MOTOR RESISTOR TEST in this article. If there is no continuity, replace resistor.
If there is continuity between motor terminals at blower connector, check for proper ground circuit. If ground circuit is okay, check for blower motor malfunction. Replace blower motor if necessary.