He asked if the coolant pump could be attached on a timer. The tech article shows how to do such a thing using a typical turbo timer as a timer. If you do it like the tech article states, the car no longer continues to run after the key is pulled out but rather the coolant fan is activated for a duration controlled by the turbo timer.

If you want to rig up a simple switch, you can connect your switch to the thermoswitch located near the coolant tank. If the switch is activated within 10 minutes of engine shutdown, then the coolant pump will activate.