How do you test an electric PTO clutch on Cub Cadet LT1050?

First of all, if the blades are spinning, the clutch is working. If the deck will not spin up when you turn it on, a diagnosing is involved. First check the deck belts and then go on to the clutch. On most any mower with an electric PTO clutch, you can test that it's actuating by sound. Turn off the mower and sit in the seat. Turn the key to "run" and flip on the mower switch. You should hear a very audible click/thunk from underneath. If you can't hear the sound of it actuating, the next easiest thing to do is remove the deck and watch it. Remove the deck and belts and have someone start the mower. Get on your hands and knees and look underneath at the clutch. It should be directly underneath the engine. Have them turn it on and then off. You should be able to easily see it start spinning and then stop. If you cannot see it work on command then it needs replacing/repairing. If this works correctly and your belts are in good condition then it is most likely a problem with deck spindles or bearings.