Mike, here is what you need to solve your heating problems.
One Ford Taurus Electric Fan - Dorman OE Radiator fan assembly no.620-101 $88.11 (new) on Amazon.com.
Mark VIII Relay Kit -2-speed fan (
Mark VIII Fand Relay Kits) Manual set up $73.86 Basic kit.
713 937-0387
He can build you a relay kit to work off of engine temp. requirements too.
This puller fan will solve your heating problems if all other systems are good.
Bill