[Tommy]

Electricity for the circuits protected by a fuse must flow through the fuse. If something has caused its contact surface to oxidize so much that electricity cannot consistently flow through it, you could get the symptom you describe. If it were my car, I would put in a new fuse and check it periodically to see if the oxidation reappeared. If the oxidation returned, I'd start looking for a reason why (e.g., water dripping on it).