Friday, the AC decided to stop running. I had a compressor capacitor laying around in the shop, and it tested OK, so I swapped out the one in the outdoor unit which tested bad. Specs matched. The unit fired right up, however, the hard start kit relay, attached to its own capacitor, was very clicky and noisy. So, I ordered another one of those and tossed it in last night at midnight. The new one is a lot quieter, but it is clearly continuously clicking when the unit is running. It sounds like cards being shuffled.

I shut the unit down because I don't know if that's right.

Is this normal? I never noticed it before, but you can't hear it much when the enclosure is on. The AC tech isnt available until tomorrow, which is fine, but I'd like to get it up and running.

Do hard start kit relays continuously 'click'?

IMO, if the clicking is coming from the actual relay, probably not normal. It should run on the starting circuit until it's up and running then change states. That said, the clicking could be from other components? Hard to say without being in front of the unit.