Are you refering to the fan/blower inside the car or the cooling fan behind the radiator?
Make sure the cooling fan is turning on when it starts to overheat. there should be more than one speed. next spray off your radiator, go to a car wash and use the sprayer, remember the a/c condenser is in front of the radiator.
If that doesnt work turn the car on take off the cap, see if it still overheats, also check to see if you can tell if the water is flowing freeley, this could mean your water pump went bad again or you need a new cap. are there any bubbles coming out of radiator, or smoke. There could be signs of a blown heat gasket, or a hole in the system. Take off top radiator hose to see if its pumping water, then take off the bottom one and if it comes out then you'll know if your radiator is clogged or not. is there a tempature difference when you touch the top and bottom hoses? you can take the radiator to a shop and have them to a flow test or clean it. the top should be hot and the bottom cold. that mean its being effective.
After that replace the thermostate. after that then your about where i'm at...stuck