No heat When i turn on heat/ac nothing happens i have tried changing fuse and still nothing not sure what to do

Unplug the blower resistor, it is located near the blower motor, check plug for heat melting or burning, This is common on theses trucks. If you see this issue you will need to replace the resistor and the plug to it. be aware that the wire connector will cost more than the resistor module. Doesn't really make much sense but what can you do?? good luck

Have you checked the relay for the system. Should be in the under hood fuse block.