Once the engine-driven cooling fan is removed and the proper bolts are installed to secure the water pump pulley, we're ready for action. Here, the Old Air fan is lowered into place for a fit check.

Where the electric pump really paid dividends was out on the road, where coolant temperatures in typical use dropped from a scorching 210-220 degrees F down to a comparatively gelid 185-195.

Our example for today's "how to" lesson is MotorTrend tech center technician Christian Arriero's 1974 Plymouth Duster . Christian picked up a Painless Performance electric fan relay kit with a ...