There are two fuses. One is red (just below relays on the wheel well) and for the positive feed for the control wire harness.
The other is up by the cdi box and is the ground fuse for the ground side of the control wire harness.
normally the ground fuse blows and is either do to head lights wired wrong or rotted starter brush spring inside the starter/generator. The brush spring on the bottom rusts out first on these.
The other area to look at is the wire harness at the battery tray. These rotted out and were replaced with after market battery trays. The new trays had sharp edges on them and would cut into the wire harness.
If it only blows fuses in one direction (forward or reverse) it is one of your solenoids or the back up buzzer (very common).
Remember to double check extra wires for lights and radio. They should have their own wire harness and not be grounded to the frame. (ground to battery only)
Grounding any extra equipment to the frame can bypass the main harness ground fuse and will burn the entire ground system in the main harness if the starter generator should short out.
This happens all the time!