Performed a/c tune-up on a Carrier heat pump system. Checked the electrical, mechanical and performance systems of the unit. I did find the primary drain line was clogged. I cleared, cleaned, flushed and treated the drain line. I found the system was not shutting off when the water safety switch would trip. I rewired the float switch to break “R” wire. I reset power and verified the safety switch is now shutting off the system when tripped. I verified outdoor wiring is secure and washed the outdoor coil. No other issues were found. The system is operational at this time.