Honda issued a limited lifetime warranty for GL1200 replacement stators, good for the first purchaser of a replacement stator; it didn’t cover the replacement stator coupler or other related parts. A repair kit is still available for melted connector blocks (Honda part #31105-ML8-305). The workaround for connector burnout is to toss the connectors and solder the wires together in a staggered formation so no two solder joints adjoin. Have a look at the connector block on your brother’s bike. If it’s blackened or melted, you know what to do. But if it turns out the stator itself is faulty, replacing it will require taking the engine out of the frame, which is indeed a headache.