Nissan 27220-7B025 Fan & Motor BLR

When equipped with the optional auxiliary rear heater/air conditioning, there are two blower motors, two blower resistors, and two blower switches for the front and rear systems. The checks for front or rear are similar, only differing in component location. Check the 65A FRT BLWR fuse in the engine compartment fuse/relay box, the 10A RELAYS and 7.5A A/C-CONT fuses in the interior fuse panel, and all circuit connections for looseness and corrosion. For the rear unit, check the no. 24 and 25 fuses. Ensure the battery is fully charged. With the transmission in Park and the parking brake set, turn the ignition switch to On without starting the vehicle. Switch the heater controls to FLOOR and the blower speed to HI. Verify blower operation by checking airflow at the ducts, then test all speeds. The front blower motor resistor assembly is located on the evaporator housing under the right side of the dash, and the optional rear blower resistor is behind an access panel. The blower operates continuously when the ignition is On, and the mode switch is not set to Off. A thermal limiter resistor is integrated into the circuits to prevent component heat damage. If the thermal limiter circuit opens due to excessive heat, replace it with an identical part. With the resistor removed, visually inspect the limiter for damage, and test the resistor block for continuity. If any resistor elements fail tests, replace the blower resistor. Locate the blower motor's electrical connector. Backprobe the brown/white wire terminal (or the red/white wire on rear blower units) to ensure at least 10 volts are present when the ignition is On. If not, there's a circuit issue from the fuse panel to the blower motor relay. If there's voltage but the blower doesn't operate, check the ground circuit. If the blower still doesn't work, replace it. If the blower works intermittently, and the resistor is fine, remove the heater/air conditioning control panel. Disconnect the blower speed switch's electrical connector and test for continuity. If the results aren't as expected, replace the blower speed switch. Lastly, test the relays for the front or rear blowers, replacing any faulty relay.

Disconnect the negative battery cable and remove the glove compartment. Disconnect the blower motor connector, remove mounting screws, and carefully extract the motor. If replacing, transfer the fan wheel to the new motor. The push nut attaching it can be removed with pliers or a screwdriver. To reinstall, push it onto the shaft. Reverse the process for installation. Some models have a rear auxiliary heater/air conditioning system, accessible by prying out the left-rear interior trim panel. The rear blower motor and resistor can be checked like the front system. The front heater/air conditioning control panel has a separate knob for the rear system.