Cooling Fan Relay Repair Procedures

Single Fan Relay System

Step 1:Locate the cooling fan relay, typically found in the engine compartment's fuse/relay box

Step 2:Test the relay by:

• Checking for power at the relay terminals
• Using a multimeter to test relay continuity
• Performing a relay swap with an identical working relay

Step 3:If faulty, remove the old relay by carefully pulling it straight out of its socket

Step 4:Install new relay ensuring proper orientation and full insertion into socket

Step 5:Test fan operation to confirm repair

Dual Fan Relay System

Step 1:Identify both primary and secondary fan relays in the fuse box

Step 2:Test each relay independently:

• Primary relay controls low-speed operation
• Secondary relay controls high-speed operation

Step 3:Remove faulty relay(s)

Step 4:Install new relay(s) matching original specifications

Step 5:Verify both low and high-speed fan operation

Variable Speed Fan Relay

Step 1:Locate the variable speed relay module

Step 2:Perform diagnostic tests:

• Check input signals from ECU
• Test voltage output at different temperature readings
• Scan for diagnostic trouble codes

Step 3:Disconnect electrical connectors and mounting hardware

Step 4:Install new variable speed relay module

Step 5:Program/calibrate if required by manufacturer

Step 6:Test fan operation at various speeds

Important Notes:

• Always disconnect battery before replacing relays
• Ensure replacement relay matches original specifications
• Check related fuses and wiring while performing repairs
• Consider professional diagnosis for complex variable speed systems