[Double Venom]

Curt,
What Don is saying, is the black magic fan turned out to be very unreliable. The built in thermostat would vary by 20 to 50 degrees constantly. We simply removed the litle "4-pin" connector box you describe, wiring it directly to a 180 degree sending unit mounted in the intake water flow.

You asked, the answers are here.

DV..PS...the "BM" fan is one of the most AMP abusive fans on the market, at least the old ones.