My 4 ton-unit AC compressor has been intermittently turning off. I replaced the old PTC hard start kit SUPCO SPP6 Relay/Capacitor Hard Start Kit with 500% Increase Starting Torque with a [b]new[/b] SUPCO SPP6 Relay/Capacitor Hard Start Kit with 500% Increase Starting Torque. I also installed a new run capacitor 35+5 mf 440/370 Volts, thinking that the capacitor may be starting to fail. The air conditioner compressor kicked right on after the installation. I went upstairs to work on some things and noticed it getting hot upstairs, so I went outside and noticed the compressor was off again. Honestly I’m not sure if the compressor failed to start back up or if the compressor kicked off while it was still running when I was upstairs. I have attached a picture of the hard start kit I installed. Any tips or suggestions?

I have an old Day & NIght model 591anx042000abaa The AC stopped working but was making a loud buzzing noise, neither the fan nor the compressor was operating. Upon inspection, the Start Assist Capacitor was blown. I replaced the capacitor and contactor, the loud buzzing went away but neither the fan nor the compressor would start. I measured 110v at both input terminals to the contactor and 24v at the contactor relay, the relay closes upon thermostat calling for AC, 110v is then measured on the other side of the contactor. I measured the resistance of the fan as follows: Yellow-Black -19.1 ohms Brown-Black. 56.6 ohms Yellow-Brown - 76.4 ohms I measured the resistance of the compressor as follows: Compressor: Black-Yellow 0.8 ohms Black-Blue 2.0 ohms Yellow-Blue 2.4 ohms In addition to the start assist capacitor, there is a dual start capacitor (Z97F9028) 50/5 uf. I measured the fan side and it was 5uf. I was not able to test the other side as my multimeter does not support a 50uf cap reading. With the system energized and calling for cooling, I manually spun the fan but the motor did not engage. I am out of thoughts on what to do next. Any thoughts on next steps would be greatly appreciated. Thank you. -Steve