I had a problem with the battery running the car down and was told the aux cooling water pump (?) was staying on causing the battery to drain. We disconnected it and it solved the problem. Now, with Texas doing its summer thing, the car is about to overheat.

Ques. #1 - How do you recomnnect the cooler fan?
Ques. #2 - Is it difficult to by one of these contraptions and install it yourself?

Do you mean the aux. fan as in radiator fan? The fan may have shorted out and runs constantly and need to be replaced.