Re: 1964 Malibu horn relay
Better for certain applications...
Let's back up. We are saying (if chosen) to protect the main charging line to the battery. We're not fusing the horns alone.
Fuses and fuse holders are NOT the choice for "mission critical" stuff like this. The wire from the battery to the horn relay is responsible for providing power in order to activate the starter solenoid, provide all the power until the alternator can or be responsible for ALL the loads if the charging system quits as well as providing the link between the battery and alternator so there is filtering of the DC in the system.
The best fuses and holders and breakers are still an introduced weak point-- for oxidation, temperature cycling, etc. When I worked for the State Patrol as a Senior Electronics Tech, you soon see with a fleet of hundreds of vehicles how even the best fuse holders, fuses, breakers, etc. succumb to not only the elements, but just age. And we're not talking vehicles used for 40 years. Some were not even subject to extreme duty fatigue.
Fusible links? Not so much. Why? It's a wire, spliced to another wire and then sealed where the splice is. It is not going to oxidize unless it is physically damaged. It's not going to get "weak" with age like a circuit breaker or certain fuse holders. They provide protection against catastrophic overload (without nuisance blowing or tripping when unexpected higher then normal increases in current draws take place) while maintaining this high level of long term reliability.
That is why they were used over a half century ago and still used today.
Fuses and breakers have their place, but I wouldn't want one in this location.
-If you don't stand for something, you'll fall for anything.