replaced the resistor , heat still not working

Bad blower motor,or control switch module,but if fan is blowwing,and just no heat ,check the blend door actuator.

You don't really give much information but if you don't have heat, but the blower works, make sure the heater hoses are warm to touch after the engine has rin for awhile. If hoses are warm or hot, could be bad thermostat, heater core blocked, heater door not working, bad vacuum line. With engine cold, remove the ehater hoses and see if you can use a water hose and try to see if the water goes into the heater core and comes out clean and with the same flow as the input. I