On arrival breaker was tripped at main panel to ac condenser. Found contactor blackened and in poor condition. Was able to run the machine by rearranging wires and found the system producing a subcool of 6. System is designed and was installed at a 9 subcool indicating the system is leaking refridgerant. Leak searched and found very intermittent pings in evaporator coil along with significant rust. Replaced contactor and respaded burnt wires with customers permission. Once completed I turned the system back on and had no high voltage passing through the disconnect. Informed customer and replaced breaker at disconnect versus replacing full disconnect. System running and cooling once complete. Recommended speaking with a comfort advisor about replacement due to age and condition of system and the likelihood of future repairs and downtime. Will follow up on Thursday around 6 to see if they would like to get quotes and get today's repairs waived with a new system. Thanks for cho