Nissan 27220-8B400 Blower Motor & Fan Assembly

If the blower motor speed does not correspond to the setting selected on the blower switch, or the blower motor does not operate at all, the problem could be a bad fuse, relay, switch, blower motor resistor, blower motor or blower motor circuit wiring. Always check the fuse and the blower relay first, then remove the glove compartment and lower dash trim to gain access to the heater case and blower motor. With the ignition key in the ON position, turn the blower switch to the faulty position(s) and, using a test light or voltmeter, check for voltage at the motor electrical connector. If the motor is receiving voltage but not operating, either the motor ground is bad (on these models the blower switch and resistor are part of the ground circuit) or the motor itself is faulty or the fan is binding. To check the fan, disconnect the electrical connector from the blower motor and connect a jumper wire between the ground wire terminal on the blower motor and a good chassis ground, then connect a fused jumper wire between the battery positive terminal and the positive terminal on the blower motor. If the motor now operates properly, the ground circuit or the blower resistor are bad. If the motor does not operate, the fan is either binding or faulty. To check the blower motor fan is binding, remove the blower motor. If the ground circuit to the motor is bad, check the blower resistor for continuity between the terminals. If any checks indicate infinite resistance, replace the blower resistor and retest the ground circuit. To check the blower speed switch, unplug the electrical connector from the blower switch and check the continuity across the indicated switch terminals with an ohmmeter. If continuity isn't as specified, replace the switch.

If the blower motor is receiving voltage but not operating, potential reasons include a bad motor ground, a faulty motor, or binding of the fan.

Begin by disconnecting the cable from the negative terminal of the battery.