Heat/ac fan willnot turn on - 2006 Chevrolet Silverado 1500 2WD

There are two different thermostats--one in the cooling system, and one just to turn on fans. The AC has a separate circuit to turn on fans regardless of engine temp, so tind the the fan thermostat and test it.

Your airconditioning system may be out of cooling gas, and if it has sufficient gas, the compressor might not pick when you put on the AC, and if the compressor did not pick ie start, you cant experience cooling effect, the fan will only be blowing.

Temperature sendin unit needs replaced it sends a signal to the dash for temp and also to the fan switch. The ac is turning on the fan because, when ac is on the car would run warmer, so the ac switch is also connected to the fan. Are you saying that the ac kicks on when iddling or that's the only time you can turn it on

we talk her about any fan ( blower ) or (condenser) fan .what you ( repaired twice ) .why you remove the dash .how many fan motor you have .
if you turn on the heat or ac the smoke start come from where . you say its fried (any part) .

The relay center is under the hood, there should be several with the same #'s switch one that you know is working in place of the fan relay, if fans turn on replace relay. It is faster to turn on ac after switching relays for diagnostics as fan should run as long as ac is on...

u may have a cooling fan relay or cooling fan out,,,, the ac may be cutting out because it needs more freon it may not be over heating the low presure swtch is responsible for that

you may want to check on the radiator fan. The AC has its own fan and once AC is on, the fan would help bring down the temperature. It is either the fan is not blowing or has become weak. You can check on the fan by pulling out the temp sensor on the lower radiator hose. The fan should blow at full speed when doing this.

Check on the water reserve the water inside it goes down, if not there may be a leak somewhere. Water vapor may be escaping and lessening the effectiveness of the cooling system. This may be a reason why the engine cools down after the AC fan is on.

Sounds like the wheel bearing on the right rear hub may be defective, that would cause the noise if the tires are ok. As far as the fan goes not sure this isn't working as designed.

bad water pump? Is there circulation in the radiator?

replace the blower motor