I have a john deere L110 that want start, I've changed the starter, battery and Solenoid. The starter will spin, but want engage the fly wheel. Now the 20 amp fuse has started blowing once I turn the switch on and off. Can someone help!

Did it work correctly before and then stop with no other changes or repairs being done? Is it possible that the polarity is switched at the battery. Normally this would be a bad starter bendix but you say you replaced the starter and the problem is still there.

It worked perfectly when I put it up for the winter, this was my 1st attempt to start it this season

The battery is connected properly as well...

So a brand new starter makes the same sound as the old one, just spinning but not gear engagement with the fly wheel.

Yes...

yes......
The thing that is really, nutz now is that the 20 Amp fuse blows after turning the switch on and off... I'm wonder is the problem in the switch?

Could easily be the ignition switch. Pull switch and check for melted wires at the back of switch.

I think you might have wired the solenoid wrong which would cause this fuse problem.

Just recheck the connections there. That seems to be the only wire catalysts in changes here on wiring. Not sure how yours is grounded so I posted a couple of setups.

http://www.arcomarine.com/xhtml/Tech%20marine%20circuts.pdf

http://www.arcomarine.com/xhtml/Tech%20marine%20circhttp://www.cruisersforum.com/forums/attachment.php?attachmentid=2616&d=1202377668uts.pdf

I rechecked the connections, everything appears to be wired properly based on the manual