Whats the reason of having it not run at full speed all the time. If your tryin to maximize fan life, and thermo switch would be the best choice.
I just have a switch inside which I can control as I keep an eye on the temp.
Skyler
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-1989 Saleen Mustang #406-
TFS TW Heads, E-303, Edelbrock intake, 70mm TB, 73mm MAF, 24lb injectors, 1 5/8 shorties, Off Road H, 3 Chamber flows, Jaz Race seats, Back seat removed, sub-frames, Roll Cage, and a 80 shot of N20.
12.54@107.4 Motor
1.69 60'