toro lx420 blows main fuse

[chucklesva]

my toro lx420 just started blowing the 20 amp fuse. it will start and run for about 20=90 seconds and then blows the fuse and the fuse holder is very hot. sounds like the fuse is doing its job. checked all grounds and they seem ok. would appreciate any ideas on whats causing the problem. i am not good with electrical so would appreciate your help.
chuck

 

[beenthere]

Rig up a 12v bulb in a socket with wires that you can plug those wires into the fuse socket. If there is a short, the bulb will be lit. Move a few wires around and see if that helps find where the short is at.