The fan is working but the engine is not sensing the messege to the fan when is hot what is?

Engine is still hot... you might need to check your coolant level.

There should be a fan relay and it may be protected with a fuse. There are temperature sensors which sense the water is hot and make the relay work.

cooling fan mainly turns on when your ECM senses that your engine is getting hot and there is no wind cooling down the coolant to cool your engine it usually kicks on when your idling or driving at low speeds to pull in the wind to cool the coolant. the fans don't need to turn on when the engine is off

if its overheating, mostlikely its one of a few things. A.) Thermostat needs to be replaced as it can no longer sense the temperature of the engine. B.) check to see if the auxillary fan is working correctly, if its not replace the fan if its elecrtical or the relay.

CHECK COOLANT LEVEL.IF COOLING FAN TURNING ON COOLANT TEMPERATURE SENSOR WORKING.BECAUSE IT CONTROLS AND TURN ON COOLANT FAN AT A SET TEMPERATURE.SOUND LIKE ENGINE RUNNING TOO HOT. HAVE RADIATOR FLUSHED.REPLACE THERMOSTAT. HAVE ENGINE BLOCK FLUSHED.REPLACE RADIATOR PRESSURE CAP ALSO.SEE WHAT HAPPENS.

This can either be..

1. A broken fan (the electric motor is damaged and wont turn)
Test it with a vault meter, find the coupling where it plugs into the relay, and see if there is a vlotage going to the fan

2. The relay is broken
If you follow the fan wiring back to the engine, usually around the radiator it attaches to a relay, this senses temperature and send power to the fan. These can fail. Breakers yard for pennies for this, a few more pennies for a fan.

Well, that makes sense because it is beyond the normal operating temperature of the engine. What you want to check is the engine coolant level and visually inspect for any leaking because the problem here could be that the engine doesn't stay cool enough. Do you hear the fan working when it gets too hot? If you don't, you might want to try to check the fuses or if there could be something more to the fan. Hope it helps.

Although rare, it is possible that the fan motor is bad. I don't know if the connectors are the same or if there is only one connector for the fans. My point is try to switch the connectors and turn the a/c on. One fan runs off the coolant temperature sensor and the other off the a/c hen the compressor is running. It basically senses a load on the engine and engages the fan. The one that works has power to it so you know if it does not run the other fan, the problem is the fan. If you have the V6, it may just not be getting hot enough for the fan to kick on. If you have the 5.7L, I would definitely confirm the fan is good because those engines are designed to run hot and they get up to running temperature very quick. Please rate me on this answer.

Fix the secondary fan.

there is a relay for the fan....trace the wires from the fan to the relay....should be on the radiator support or the housing for the rad.