donn0128 wrote:
Go up on the roof, take the four screws holding the shroud in place off, lift the shroud off and have a look.
Yes, sounds like you have a corroded/burnt wire arcing in the capacitor housing. Especially if 20 years old. Also, start the AC on FAN only and see if you have the same click. If no click, that rules out debris and points to the Compressor wiring/capacitors having a problem. Disconnect 120 power when accessing the capacitor housing. That is a metal box with some hot wires and may give you a jolt if indeed melted/shorted. Doug