1994 bayou 400 4x4..i replaced the main 30 amp fuse with a 30 amp 12 volt circuit breaker.will this cause problems in charging circuit?

 

A 30 amp fuse and 30 amp circuit breaker perform the same function,difference being most circuit breakers trip and reset if there is a problem versus having to replace a glass or blade fuse when they pop. Only problem is if it's been popping fuses you need to find the source of the problem and not rely on a circuit breaker.Some circuit breakers may take longer to trip and could cause problems on wiring.