20 AMP FUSE BLOWS WHEN IGNITION IS SWITCHED ON IGNITION SWITCH TESTED AND OK

hi there.
see if this link helps you out.
2001 suzuki lt300 20 amp fuse blows Google Search

CK WIRING HARNESS FOR SHOT TO GROUND

wire up headlight globe into the fuse position that blows, headlight globe will glow very bright when short is there, careful you dont have globe on things that can melt or burn eg. plastic or carpet etc..glass and area around it gets hot
now everything will work but the circuit that has the short to ground and you wont melt wiring or cause dammage to other components. you now need to disconnect connectors and components one at a time to work out which section of wiring or component has shorted. to work this out a wiring diagram would come in handy. when the globe goes out or is very dim as in filerment element in globe just glows red like heater element short is gone.

This could be the starter or the ignition switch, Take the starter out and have it tested. IF the starter tests ok, replace the ignition switch.

problem could be radio.10 amp fuse for ignition switch power up radio display the 30 amp fuse for radio amp system in which that circuit hot at all times.

must have a short probably in steering column dad had blazer in shop doing same thing we found short in ignition switch

most likley the fuel heater is bad and shorting out happend to me replace the heater

have your starter tested at your local auto parts store to see if it's drawing to much current

there is a dead short in the wiring for that fuse what does the fuse go to??