On arrival, I found that the thermostat was powering on and off for each call of cool. I went outside and found that the contactor relay was shorted out and also burned up on the high voltage side due to the aluminum wire not being properly secured or having any anti-oxidant compound. I spoke with homeowner and he approved the repair of the relay and also going ahead and proactively repairing the run capacitor as well. I installed a new contactor relay and new capacitor at the outdoor condenser, I also applied anti-oxidant compound on the aluminum wire from the breaker to the condenser and tightened to 40-45in-lb of torque per manufacturer guidelines. Cycled high voltage power to system and verified operation. Everything is working at this time.