Hi, Anonymous before diagnosing your blown fuse issue, check the bottom of your seat, if it's metal and comes in close proximity to the positive battery post you need to take the necessary steps to ensure there is no contact (electrical tape, thick rubber insulation, hammer a dent in the seat bottom etc.) You are going to need a wiring diagram from your service manual, a test light, an ohmmeter and plenty of extra fuses.
If you turn on your ignition switch and immediately blow a fuse you have a hard/dead short and is usually easy to find. With a test light connected to the hot side of the blown fuse holder start stabbing the wire/s that leads away from the fuse holder and towards the ignition switch, you test light will illuminate validating the short. When the test light fails to illuminate you have passed the short and need to back up until the test light illuminates, then look in the immediate area for the short.
If you driving down the road for 30 minutes or 15 miles and blow a fuse you have soft/flying short and may take some time and patience to find.
If the main fuse/circuit breaker constantly blows/trips while riding you probably have a faulty battery terminal connection. Check battery terminals for damage or corrosion, check battery cables at "BOTH" ends for loose, corroded, or broken connectors, "INSIDE" and outside the cable harness, perform connector wiggle test and check cables with an ohmmeter if necessary. Any other fuses that constantly keep blowing while riding are usually caused by a loose or corroded ground wire in the circuit, which means you have to check, inspect, test each and everyone with an ohm meter set on a low ohm scale 100 ohms or less . Simply touch one lead to the ground source and the other lead to the battery negative terminal, a reading of zero indicates a clean solid ground. Any number reading or infinity indicates a poor ground and needs to be repaired. Poor or weak grounds require excessive additional amperage to complete the circuit which in turn blows the small amperage fuse.
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keep blowing the 30 amp fuse
main fuse keeps blowing
Honda Shadow VT1100 Owner Manual
Honda shadow vt1100 Owners Workshop Manual