DIY Series 82: Car Aircond Blower Fan Relay

Proton Saga BLM Aircond Blower Fan Not Working

Symptoms:

• When turning the Fan Speed Control Knob at Aircond Control Panel, the blower fan of aircond is not working.

Possible Issues:

1. Blower Fan Motor malfunction 
2. Blower Fan Relay malfunction
3. Aircond Control Panel malfunction (very rare case)

Findings:

• Take out the blower fan motor (under glove compartment), test it directly by connecting to 12V car battery terminals, blower fan motor is working fine.
• Checked the wire connector before blower fan motor using multimeter, there is no supply (12V) to blower fan motor. 
• Check the blower fan relay, found out it is having burnt mark. Replaced with new relay (PW537074).

Photos:

1. Understanding the circuit diagram of Blower Fan Motor 
2. Common Relay (PW537074) Circuit Diagram & Pin Configuration
3. Order a new relay for part replacement
4. Unscrew 2 screws at the cover under steering wheel (right side)
5. Unscrew 2 screws at the cover under steering wheel (left side)
6. Dismantle the fuse compartment cover
7. Dismantle the cover under the steering wheel
8. Identify the relay for blower fan motor (located at the middle of 3 relays)
9. Replace malfunction relay to a new unit
10. Further analysis, found burnt mark at the malfunction relay

Tools:

• Screwdriver
• Multimeter

Costs Involved:

• Blower Fan Relay (PW537074): USD$1 ~ USD$3