Scag 52" Hydro Safety Issues

So i was using my mower the other day and it would not stay running if I messed with the plug for the brake handle safety it would either run or die. So i order the safety switch for it and put it on. Well it wont start with the brake on so I start it with the brake off.. If i pull the brake it dies. The blade pto also kills the mower if i engage the blades. But if I just barely pull on the pto it will engage the blades but when i pull the pto all the way out it dies. It is the SWZ52A model