This is for my van, but I just thought I would post it because the same idea can easily be applied to a F-car or whatever. Benifits include greater cooling at idle, colder a/c at idle, and better mpg when the fan is not required. I am making a small change to my cooling system. Going from the mechanical clutch fan to a dual fan setup run by the PCM. I had it rigged up one other time, but this time I am setting it up RIGHT! The shroud will be rigidly mounted to the frame of the radiator with bolts, no plastic zip ties through the core. The bolts will go through the mounting points on the shroud into holes I am drilling in the top/bottem support tube (dry without coolant). A 40 amp auto-reset circuit breaker protects the circuit, 2x30 amp relays, and its ECM controlled. Even the crimp connections are soldered or will be. Everything is getting heat shrink, electrical tape, and wire loom as well.

Here are the settings I will be running. Both fans run on either low or high at the same time.

Low Speed

On 190
Off 185
Off @ 40 mph
8A draw

High Speed

On 195
Off 190
Off @ 45 mph
25A draw



The only things not readily apparant in the picture are the massive thickness of the radiator 28" core by 3" deep and the volume of air these fans can move on high speed at a full 13.8-14.2 volts.

 

Just an update now that I have been running these fans for 2 weeks. The ECM controls them flawlessly. When the engine gets up to operating temperature the thermostat opens and coolant starts to flow through the radiator. After about 10 minutes of idling the low speed setting kicks on. The fans run roughly 1 minute on low speed and turn off. It takes another 3-5 minutes for the fans to turn back on again. I have not once seen the fans running on high speed, other than when the a/c is on. When the a/c is on the fans both run on the high setting until the MPH shut-off is reached. Works great with very little noise. Throttle response is much improved and running down the road at 70-80 mph in this heat you can definately feel an improvement in HP/TQ over a locked up fan clutch(they lock in this heat). The fans pull more air across the condensor at idle than the clutch fan could ever dream of. My TPI 305 idles at 600 rpm in Park/Neutral and the A/C blows 45*F (102*F and tons of humidity) out of the vents both front and rear.

 

What is that fan setup off of?