Recently I had to pull a friend’s trailer with my F150 pickup, and discovered the trailer had a wiring fault causing a short and blew a fuse on the trailer brake circuit. I popped open the hood to get to the fuse box up in the passenger side of the engine compartment, and found that many of the fuses are a newer style than the traditional blade or mini blade fuses.
Turns out, these new fuses are difficult to source. They weren’t available at the local auto supply, and the dealers want ridiculous prices for even a single fuse. Apparently these are a relatively new style from Littelfuse called “MCase+”. On top of that, the MCase+ comes in a slotted and unslotted variant, of which mine are the slotted variety.
I could find a small quantity of these style fuses in larger 100+ fuse variety packs sold on amazon, but a huge variety pack of fuses I’ll never use would be a waste. Fortunately I found that one of my usual electronic components suppliers has them in stock, and I could order them individually. Here’s the 20A for example. So I ordered a couple of the most common ratings I saw on my pickup to have a small set of spares without all the waste.
I’ll also note that the truck has an additional fuse block in the passenger foot well, which uses mostly more traditional mini blade fuses, though it does include some unusual three prong mini blades as well.