Had to reinstall Mach 3. Now Auto Z setting not working.

There is no Auto Zero function in Mach3, you have to add the macro code to the button yourself.
So, if you had it working, the reinstall removed it.

Ok can u walk me through that or give me some steps

If you have the macro, go to Operator > Edit Button Script. Click the button, and paste the macro into the editor, then File > Save.

This is what was in there when I checked the macro.

I'm guessing the switch that controls the home to z is stuck to active and needs to be replaced. When I go to zero all
In top left ref z nothing happens. Go to Cnc and press and hold button and ref z and it will move the head.