Fans wont come on at all in my chevrolet silverado 2007 it will run hot if we are still but, if we get moving the engine cools down immediately

I hope I don't live to regret this...When you first start your motor it is cold. It does not need a fan. When it gets hot the fan will come on bringing the temp down so the fan no longer needs to run. When you drive down the freeway the fan does not need to run because it has plenty of air flow. But when you are not moving the fan needs to cool things down so it will cycle on and off.

Fans that cool today's engines are electric. The fans operate when the engine temperature rises above a certain point. When you shut your engine off and are no longer moving, air is not flowing through the radiator, but the engine is still hot. Fan goes on to keep the engine from overheating, it's normal.

cars have 2 things.
engine coolant temp
and HVAC temp
can tell what you are talking.

car is off state?
do you mean the engine stalls.?
try to talk in terms of what system in car is failing
HVAC (heating or cooling of passengers)
engine issues, stalls , misfire, lost power.
transmission issues, wont shift or slips or messes up some of 100 ways. as a/t love to do.?

Fan will run for a certain period of time after shutting down motor of vehicle. This is normal. Your engine is still hot when you turn the key off. There are sensors that tell the computer when the engine is cool enough for the fans to shut off.

This sounds like a bad coolant temp sensor that give computer false reading, check the coolant temp sensor connector and if it is good with no bad wires to connector then replace coolant temp sensor , when the computer gets a signal from temp sensor that engine is hot it turns fans on high speed to cool radiator and displays a/c turned off , if this truck does not have electric cooling fans then they wont run just explaining what happens depending on engine and cooling set up. replace coolant temp sensor and check connector.

Does the engines electric cooling fan turn on when it gets hot? Does it cool off if you turn the AC on?

Most have a sending unit near the thermostat housing or on the cylinder heads. Ask the parts store which sending unit you need for the fan control. If you change it with the engine cool you will not get burnt by hot antifreeze. Some newer engines run the fans through the computer. I wish they would not change the engineering all the time. Good luck.

Have you checked the thermastat too because this part also goes bad and does not open up at its temperature range to allows the coolant to go through the engine to cool it off. Usually when the fan comes on is at a much higher engine temperature so you would have to run the truck just by having it idle for 5 or 10 minutes so the engine gets hot and you should see if the fans come on to help cool the engine down to its normal temps.

the coolings fans are designed to run for a little while to dispense heat they dont do it all the time turn usually during higher hot days w/ac on or higher hot days goes off automatically

You are talking about the thermo electric cooling fan, its operation is independent of the car's electical system. It is switched on and off by the engine temperature. When you park, the engine heat soaks upward to heat the thermostat turning the fan on. It will run until the engine cools down and the thermostat switches it off. Quite normal operation.