It cools, but I still hear the fan motor running. even if I turn the temp to off.

disconnect the cooling fan motor connector and run jumper wires from the battery to the fan motor. if the motor does not run then it requires replacement. this is a common problem. if it does then it could be the fan relay, wiring/connection problem, temp sensor problem for the PCM to turn on the fan, even a PCM problem.

you may have a bad fan motor that needs replacing. if you unplug the cooling fan and direct feed the motor with jumper wires and it doesn`t run then the fan motor needs replacing. this is what it sounds like as it should run when the motor gets to a certain temp or the a/c is turned on.

Could be either one, but usually its the fan motor.
You can run a wire direct from the battery to bypass the relay to see how fast the fan is able to run. The connector on the fan relay can become damaged too.

ECT sensor.
Engine Coolant Temp sensor is faulty.
When motor gets certain temp, this "Plugtype" sensor is supposed to turn on fan.

I think yu have air trapped in the system. You need to burp the air. Try leaving the cap loose and running till it warms up, then tighten the cap and keep the reservoir full.

Sounds like then fan has died or the run capacitor has die. All motors that run on single phase mains need a capacitor to start them spinning. These are quite cheap & simple to replace usually - worth just replacing if you feel you can't test it. Looks a bit like a 'D' cell battery with 2 leads hanging out. Could also be that the unit is not cooling/heating and the temp sensor will not activate fan until heating/cooling coolant has passed room temp. - Rick

cooling fans will run until the desired temp is met , even if the motor is off , Its Normal

You have two fan's on your truck, 1 is a fan clutch runs with the drive belt, 2 elec fan motor, with test light and engine running at normal temp, just a little bit above 1/2 way on your temp gauge check voltage at elec. cooling fan harness if you have voltage at one of the two wire's and fan don't turn on, bad cooling fan motor, on the fan clutch after you check voltage at elec. fan motor turn engine off, with your hand spin drive belt fan if it spin's freely bad fan clutch, replace it.Also check cooling level.Hope this was very helpful

No its not true,the cooling fan comes on when the coolant temp reaches a certain point it closes the switch in the temp sensor wich in turn closes the relay and powers the cooling fan,the reason it comes on with the A/C is that it's wired to bypass the temp sensor and associated relay because the A/C compressor forces the motor to work harder and the coolant temp to rise significantly faster,the relay needs to be replaced or you will overheat the motor and possibly cause serious damage.

the fan motor is stuck take front cover off reach inside and turn fan by hand then try agin let me know