I have a Deere 240 skid steer around 2000 model that blows a 25 amp F1 Accessories fuse as soon as it is inserted. The machine runs fine but does not charge, no lights, etc. because of the fuse. I have tested the relay for resistance, and swapped it for another one. No change. Relay seems good. Seems to get a little warm just sitting there. I measure 12.3 volts across the blown fuse. This goes away only when I unplug the relay. No other fuses have voltage across them with the key off I unplugged the fuel injector and no change to this voltage reading. New alternator. Unplugged the alternator resistance relay, no change. Any ideas? I have a service manual.
Update... Turns out it only blows it when the key is in the accessories position. I inspected all lights and removed all bulbs. In the upper left position of the instrument panel is a yellow wire plug and if I disconnect it does not blow the fuse. But I can't find where this goes.