Small Engines (Lawn Mowers, etc.): Blades on mower wont engage..., electric clutch, clutch mechanism

Question
John Deer riding mower -Hydra 165 about 20years old..

There is a switch(electrical)..used to turn the cutting blades on/off...today the switch didn't do anything..couldn't cut the grass...

What I need to know is how this electrical switch engages the blades...so i can get it going again...

Does a selenoid engage what looks like a clutch mechanism...or just how does it work?  

Answer
Hi Brian,

Sorry for my delay.  The holiday was busy here.

You are on the right track.  The switch sends power to a solenoid controlled "electric clutch".  Listen for a clicking sound at the clutch.  If none, check for power at the clutch.  Usually the clutch fails but it could be the switch.  It would be nice if you only needed a drive belt.

Good Luck,
Michael

I am swamped with questions and won't be able to take follow up questions until next week.  Sorry.