Coleman RV rooftop air conditioner shows F5 and the compressor does not start or cycles off quickly.

Safety: Disconnect 120V power to the RV. Compressor circuits carry high current; use caution.

• Check RV voltage: Use a voltmeter at the RV pedestal and inside distribution panel. Low voltage (below ~108V under load) can cause F5. Correct shore power issues or reduce load.
• Inspect and clean condenser coil: Remove the shroud and clean the condenser coil on the Coleman-Mach unit with coil cleaner and water.
• Test start components: Locate the compressor start capacitor and PTCR (if equipped). Discharge the capacitor and test its value. Replace any weak or failed components with Coleman-Mach specified parts.
• Listen for compressor: After restoring power, listen when cooling is called. A loud hum followed by a click indicates a locked or overloaded compressor.
• Professional evaluation: If new start components and proper voltage do not resolve F5, the compressor may be failing and require replacement by an RV HVAC technician.

Note: Do not repeatedly reset breakers or run the unit on marginal power; this accelerates compressor failure.