Cadillac: radiator/miss, head gasket, coil pack

Question
1) How can I make the cooling fans stay on all the time?  My car gets hot with a/c running in stop and go traffic and even when I turn the a/c of it still is not cooling down.  I am going to flush the system tonight (by the way where is the drain plug and whats the easiest way to do it)
2) My car is running rough and they told me it was the coil pack but didn't tell me which one. How can I find out without changing all 4.
thank you for being there.
cars is 93 sts 4.6

Answer
You could have a faulty thermostat or a restriction in the radiator or a leak in the head gasket. Numerous tests need to be performed.

As to running rough you also need to have numerous tests performed. I can guess at replacing parts all day but until you perform some complex tests you won't know for sure what your problems are.