Cool!
At least you can start and use it without blowing a fuse.
Quickest check to separate wire problem from glowplug in the glowplug circuit, is to lift the green wire that connects to the bussbar that ties all 3 plugs together, and see if it still blows a fuse. If it does, the problem is in the glowplug wiring or the keyswitch. If it dosn't, the issue is in the 3 plugs. If you have a volt/ohm meter, you can lift the bar that ties all 3 glowplug power input terminals together, and measure the resistance of each plug individually to ground. This should help identify a single bad plug...
Since you said it is blowing the main fuse and not the glowplug fuse(both 30A), I am thinking it is probably a problem with the wiring or keyswitch...
The attached schematic I drew from my 05 284's wiring may be of use...