Filter, airflow, capacitor, charge, ducts: the sequence that finds the cause without buying parts on guesses.
Diagnosis, repairs, and full systems in published ranges, and the repair versus replace arithmetic.
What clicks, what glows, what proves flame, and the safety lines that come before any repair.
The 5,000 rule, refrigerant reality, and the duct question that changes replacement quotes.
Long inland summers, post-war ducts, and a 130 degree attic. Why La Habra replacement quotes that skip the duct read are priced wrong.