Coleman air conditioner displays E6 and the compressor does not start or shuts down quickly.

High-voltage safety: This work involves 240V circuits. Turn OFF the outdoor disconnect and breaker. Only proceed if you are comfortable working around high voltage; otherwise call a technician.

• Inspect power connections: Remove the electrical panel on the Coleman condenser. Check that line lugs on the contactor and disconnect are tight and not burnt. Tighten loose screws with power OFF.
• Check the contactor: Look for pitted or welded contacts. If the contactor is badly burned or stuck, replace it with a Coleman-compatible contactor of the same coil voltage and amp rating.
• Test capacitors: Discharge capacitors safely by bridging terminals with a resistor. Remove the dual run capacitor (and start capacitor if present) and test capacitance with a meter. Replace any capacitor more than 10% out of rating.
• Attempt a restart: Restore power and call for cooling. Listen for the compressor: if it hums loudly then trips, it may be mechanically locked or drawing excessive current.
• Measure amperage (technician-level): A clamp meter on the compressor lead can confirm locked rotor amps. If LRA is exceeded repeatedly, the compressor is likely failing.
• Next steps: If new capacitors and a good contactor do not resolve E6, the compressor itself may be failing and will require professional replacement.

Warning: Do not bypass safety devices or repeatedly reset breakers; this can cause further damage.