I got a condenser fan off of a 93' 4runner to help with AC/engine cooling at idle/low speed. I already got the thing mounted up the way I wanted it by modifying the hood latch support bracket and moving the fans mounting points around where I needed them. now I'm to the point where I need to decide on how I'm going to turn the thing on and off but I keep going in circles about how I want to do it. The ideas I have been kicking around have ranged from simply tying a relay into the compressor clutch to using a PWM fan controller module off of a newer vehicle so I can be able to ramp up the fan speed and vary it depending on condenser temp etc. here are the options I have considered:

Tapping power off of the compressor clutch wire for a relay.
paralleling a relay coil across the idle up vacuum solenoid.
using a snap disc type switch on the condenser inlet or outlet to switch on the fan relay (possibly using one on the radiator too).
adding an additional pressure switch to the high side to turn on the fan.
switching the stock binary switch to a trinary type switch.
using a fan PWM fan controller and a thermistor or two for temperature sensing

Some of the things I have been considering are:

Not constantly having the fan turning on and off over and over to save the fan motor brushes, relay, etc.
I learned after the fact that this fan was originally used with a dropping resistor and bypass relay so it would run in a two-speed configuration (so maybe starting it on full blast isn't good for it?).
I also might need to work in some sort of delay so that the fan doesn't turn on at the same time as the compressor clutch to help spread the load out, I think the alternators in these trucks were rated at 75 amps or something? so having two large loads switching on at the same time might not be a good idea.
I like to try and use automotive grade parts when possible and the only way I have seen to go with a thermistor and have a PWM fan controller is to use an Arduino micro controller between the two to convert the thermistors variable resistance to a duty cycle pulse the fan controller can use. So, I would have to mount and make all that stuff waterproof.