I do like how you have a 'soft start' control. Would be very keen to find out how you did it. For my system, I used a volvo 2-speed relay (Same fan, different shroud. Relay found in almost all 90's volvo's), in conjunction with a BMW two-temp switch plumbed into my coolant hose adapter on the return side. Switched on by a simple hi-amp relay via ignition-on.
FWIW that is an SPL/McCullogh rad
__________ Version 3.02 - Driven like it's supposed to be!