Gen IV & Vintage Air

[MDPotter]

I've been thinking about this setup on my dad's 64 for a few weeks am not convinced it's right or maybe I just don't understand it. It's a Gen IV 5.3 with a Dewitts radiator/dual Spal fan setup. The radiator/fan setup came with relays and a harness and we used the trigger wires from the PCM to control them and my understanding is that the PCM turns on the first fan when the coolant reaches somewhere around 210 and the second comes on when it hits 230 or so. I don't know if these fans have a low/high function or not, they've only ran at what seems to be full blast.

We took the truck to a local shop to have them charge the Vintage Air system as they have experience with them. We had previously installed the trinary switch, but the shop told us we need to install a 3rd relay to control the fan so it comes on whenever the compressor is engaged. The other day, it was in the 70s and sitting idling, the compressor would engage for a few seconds at a time, so the fan was cycling every few seconds. Is that the correct operation? It just seems like the fan is going to get worn out with that much cycling and at this point I don't even know what the trinary switch does.