At 10:44 AM 7/23/2011, Kenneth Lewis wrote:
>One possible alternative.   http://tinyurl.com/3mo2qok

30 amp (max) controller, 37.5 amp (rated 450W) fan...

What's the resistance of the fan resistor?  It's a two-stage one,
correct?  The smaller non-AC fan is a two-speed motor that doesn't
use an external resistor.

I suspect the unit might be usable if you run its primary output
through a resistor and then parallel the secondary output
direct.  That could depend on how it's wired internally, but on the
face of it I think it would work.

I'm not yet convinced that engine temp rather than radiator temp is
the desirable control input.

Yours,
David