My matag washer #pav2300aww won't quit filling I think it is either the pressure switch or the control on drum . How do I repair?

It is either the pressure switch or the water fill valve. For pressure switch and the tub full you should have no continuity from V to P and continuity from V to P. With tub empty you should have continuity form V to P and no continuity from V to T. Check the tube on the pressure switch for cracks. You can also blow through the tube and listen for a click. If this is OK, look where the water enters the tub and see if it is still flowing in. If it is and the pressure switch is good then the water valve is bad.