Downstairs system had a low voltage short in the condenser outside. The short was in series with the high pressure switch, keeping the contractor from energizing. The shirt was spliced and the condenser coil was thoroughly cleaned to remove dirt and debris. The filter was checked and is clean. Also inspected the circuit board and found system wired for “TWIN†on the low voltage terminals, rewired the board correctly for this system configuration. System was tested and is working properly at his time.