with heat on when I turn to defrost it automatically kicks on the AC

Thanks I will give that a try...So you think it is not an issue with the switch itself?

Which switch? Re-read BOTH replies.

What ziptie12 is saying is there are a few things you want to be aware of.. All the AC button does is control whether or not the compressor is activated or not. It is normal and programmed into the control of most car for the system to activate the AC compressor automatically when the defrost is selected. However - If you activate the defrost immediately upon starting the car when the engine is cold you would not get heat because the heat is generated by the engine coolant. Make sure the engine is warm at operation temperature you and should get heat at the floor and the face settings. Make sure you have heat in all other modes (face and floor) then move the selector to defrost and see at that point if you can still get heated air even with the AC on. If in the defrost mode you lose heated air knowing that it works in the other selections that you may have an issue with the stepper motors that actuate the flow of heated and cooled air and in the defrost mode which is completely different than the AC function being activated itself. If you don't have heat in any mode floor or face there can be a handful of issues that would cause this. Understanding how the heating system works is key. A faulty thermostat, heater control panel or the unit where the blend doors reside can all affect this. This is something that a trained mechanic may need to diagnose. Answer these questions. With the heat on and the temperature in the hot setting select the face setting, can you feel hot air blowing out of the face vents? Then select the floor setting and see if you if the hot air redirects to the floor. Without adjusting the temperature select defrost. Do you still get hot air at the top of the dash out of the from the defrost vents? Try this and let us know what happens.