When we wire the fan to come on wth the comp, we use the relay circuit that is already there ..so it is ISO.
And if one is in hot climates , the fan is on most of time anyway..that is why the new models use fan all the time comp runs..

Another hot climate change in use by many is they rewire the low aux fan circuit to come on with pressure as stock , but they wire it for high speed vs low.
This requires larger gauge wire and moving the Resistor wire to the high side circuit.

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A Dalton