I don't want a manual toggle, I don't want it to run continuously with the compressor and I don't want to open the refrigerant system to add a high temp switch. Sounds like an external temp switch is the way to go. Questions is, at what refrigerant temp should the switch close? And what does that translate to in condenser fin temp? I guess I can take a thermometer to cars with aux fans and see at what temp the aux fan comes on. I was hoping for an established rule-of-thumb or range.

I guess I can use a temp switch like compu has but I don't know that 190*F at the condenser is an appropriate setpoint.

Sixto
87 300D