I have a John Deere 170 riding lawnmower. I can turn the key to start the engine but nothing happens. I checked the battery, it's OK. With a test light, I checked to see if I had power to the starter. Yes, I have power. I can hear the blade click with I turn the blade switch on. It sounds like a safety switch is not working causing the engine not to start. I have one safety switch under the seat. I bypassed this switch but it will not start. The clutch has to be pushed in to start but I do not know where this switch is. Does anyone know where the clutch safety switch is located on this mower????