My friends Snapper 19hp tractor is having a rash of electrical problems. Battery was discharging every time he mowed. I checked the regulator and stator. Stator reads 27.8 vac. regulator output is 17.5 vdc. Battery reads 12.8 static and 13.9 when running. Tried turning on the electric clutch to check voltage at the battery. The switch did not turn on the clutch. I had found two or three bare spots on one of the blue wires that come from the clutch switch to the seat safety switch then continue to a relay next to the solenoid. How does one check the relay?