my heater and my air condition has stopped working

Switch or fan motor. Check for power at the motor, if it's there it's not the switch.

Check the resistor block it is located in the firewall on passenger side. Also could be blower motor. Also located on passenger side

Lately, I've seen a lot of faulty fan motors working yet drawing enough amperage to fry the switch and connector. The resistor block will cause the fan to blow on High only since it bypasses the block and supplies power directly to the motor from the switch.

no .. all not for my 2002 grand marque i cannot get warm air with vent or any air on any setting is this the computer? what do i do there replace computer only ??