On my fuse block legend the place that is labeled 30 amp ACC relay is actually a fuse (buss type 30 amp). According to your attached DWG, the fuse should not be energized unless key in run or accessory position. My fuse terminals are hot with key "off". Wonder if ACC relay has failed? I don't see one in fuse block like there is for starter and turn signal? All I know is if battery in tractor with good connections, every 30 amp fuse blows while installing. Don't know where ACC relay is but gonna look for short in 7 pin connector. If I forget about this fuse and circuit, tractor runs fine as long as positive and negative lugs tight.