Thermostat or control shows E5 and the compressor does not start or shuts down quickly

Safety first: Turn off power at the outdoor disconnect and main breaker. Capacitors can hold a charge; do not touch terminals without proper discharge procedures. If you are not comfortable with high-voltage work, contact a professional.

• Inspect wiring and contactor: Remove the service panel on the American Standard condenser. Look for burnt wires, melted insulation, or pitted contactor contacts. Tighten any loose lugs with power off.
• Check the dual run capacitor (visual): Locate the capacitor (usually a metal can labeled C, FAN, HERM). If the top is bulged, rusted, or leaking oil, it is likely bad and should be replaced with the same microfarad (µF) rating and voltage.
• Listen for compressor behavior: With power restored, have someone set the thermostat to cool while you listen outside. A loud hum followed by a click without the compressor starting suggests a hard-start or locked-rotor condition.
• Do not repeatedly reset: If the compressor trips on overload repeatedly, shut the system down to prevent permanent damage. A technician can test compressor windings, measure current draw, and install a hard-start kit or replace the compressor if necessary.