But the glow plugs are on a fifty. Maybe it’s been tampered with. Could the alternator be blowing it. There ain’t that many high current devices on there. Lights, to they come on automatically? Fuel solonoid? The stuff is so compacted it difficult to run down
I traced out the basics...
A thick wire goes from the positive terminal on the battery to the starter.
The same terminal on the starter you have a wire coming back to the 40a main fuse (by the battery, in the front of the tractor)- the other side of this fuse goes to the ignition switch and the fuse panel (on the side of the engine, next to the ECU)- I think probably to power the glow timer which could be on if the ignition switch is not.
Then the terminal on the starter also has a wire coming back to a 50a fuse, the other side of which goes to the glow plug relay.
And then there's a fourth wire to the same terminal on the starter which has a wire coming back to a second 50a fuse, the other side of which goes to the alternator.
So if I understand correctly, the 40a fuse that is blowing does not have any relation to the alternator. The lights are off. I'll have to see if I can figure out how the fuel system works.
I have verified with photos I've found on this forum that other people with the same tractor have the same 40a,50a,50a (green, red, red) fuse setup in the front of the tractor - so I know it hasn't been modified.