Lewmar replacement fuse for bow thrusters from 130A - 500A. The fuse holder is usually installed near the bow thruster or the buffer battery. Before replacing the defective fuse, the cause of the defect should be investigated. Due to the high currents, there is a risk of fire if the power supply is faulty! A spare fuse should always be on board so that the bow thruster can be used for the next mooring.