Safety: Disconnect 120V power to the RV and verify power is off before touching the fan or motor wiring.

Check fan movement: With power OFF, spin the indoor blower wheel by hand. It should rotate freely. If stiff or seized, the motor bearings may be failing or debris is lodged in the wheel.
Inspect capacitor: Locate the fan or dual run capacitor in the rooftop unit’s electrical box. Discharge it safely, then test capacitance. Replace if out of spec.
Verify wiring: Ensure all fan motor leads are securely connected to the Coleman-Mach control board and capacitor terminals. Look for burnt or discolored connectors.
Test operation: Restore power and call for fan-only mode. If the fan still does not run or F3 returns, the motor is likely defective.
Replace fan motor: Remove the blower housing and motor assembly per Coleman-Mach service instructions. Install a compatible replacement motor and reassemble.

Note: Mark wire positions and take photos before removing the old motor to ensure correct reconnection.

Coleman RV rooftop air conditioner shows F3 and the fan may not operate correctly or at all.

Possible Causes