Came out to call for a system not cooling properly. Customer stated that the thermostat was reading a code that stated thermostat had no power. I checked system over and found the 3 amp fuse blown on the system. Put a resetable fuse in and checked wiring. Found short at two wire on condenser and also the contactor pitted. Discussed with customer about repair needed and the suggested replacement of the contactor. Customer approved repairs. Fixed wire issue and replaced the contactor on the system. Added common wire for thermostat and cycled unit on. Checked amps, temperatures and pressures of condenser. System is now cooling properly. Recommended maintenance plan to keep system running.