Goodman Thermostat Wire Color Guide for Troubleshooting Color-coding in Goodman AC wiring is essential for safe HVAC repairs and fast troubleshooting, helping technicians and homeowners identify thermostat wires, compressor leads, and fan circuits accurately. This guide covers Goodman wire color conventions, thermostat wiring colors like red for twenty-four volt hot and white for heat, best practices for labeling and documenting nonstandard wiring, and safety steps including de-energizing system