I have a 98 Jeep Cherokee Classic (4.0). Is the electric fan supposed to come on when you turn the ignition on, or only when the air conditioner is on? Also the clutch fan seems to turn too freely is this normal or should it have some resistance?

check it on a cold morning(cold engine) it should have some resistance . its a thermostatic clutch fan and it has fluid inside that reacts to temperature. when the car is at normal temperature it will have no resistance
but when the temperature goes hot the fan begins to gain more resistance (fluid reacting to heat)to pull more air through the radiator. an early morning check just insures that the fluid is still active inside the fan clutch.

your secondary fan is used primarily for your ac system. it helps the condenser cool the ac fluid and help cool it enough too turn it into liquid form. with your ac ON (or defrost mode) the fan will ether cycle or stay on all the time. the second purpose is for it to kick on when the cooling system cant keep up on the job. for example, i was in a drive through with ac off and i could here mine click on. i noticed my temp was around 220, not dangerous but a little worm. it was not a hot day. i checked it out and found my coolant low, did a pressure test and found a cracked radiator.