Last November replaced the thermostat...didn't help....took it in to have the radiator flushed. The factory fluid was like sludge and had solidified in the radiator. Replaced the radiator...Replaced the water pump...all new fluid and it still over heat's after driving it about 20 miles. The dash gauge came on it was at about 240-250 degrees. I pulled over to let it cool down and noticed the fan on the radiator wasn't kicking on. So I turned on the A/C to force the fan on...nothing....I'm at my wits end with this issue!!!! Any ideas??? How do I check the relay switch on the fan? Could it be as simple as a fuse?

 

moved your post and started a new thread for you. welcome to the forum. yes it could be fuse or relay. have you blead the air out of the cooling system. make sure radiator is full. sometimes if the orange and green antifreeze is mixed it will turn to gunk as you are seeing. did you flush the heater core as well? should have two fuses for fans, one is 40 amp, one is 10 amp. should have three fan relays.

 

You should grab the manuals for the manual section. They will have a trouble tree as well as a diagram. Since your system is failing for both temp and AC it should be pretty easy to figure out. Relay, fuse, fans themselves. You will need a test light and maybe voltmeter/Ohm meter depending how deep you need to go.