I found this video just being curious about where and what fuses protect which circuits. It's on my saved videos list now. Might come in very handy!

 

I believe there are 3 fuse boxes on the x260 (engine compartment fuse box) (passenger fuse box) and (trunk compartment fuse box). On the top covers of these boxes have labels on them corresponding to the amp ratings. Let's say if your dome light is not working, and you verified the light is OK, then verify the fuse, you have to look at the passenger fuse compartment. Assuming the tail light isn't working and you found out the light is OK, then verify the fuse on the trunk fuse box. Same with the engine fuse box if the horn isn't working then you have to test the fuse on the engine compartment fuse box. Also, the owner's manual fuse box diagram are printed more clearly and easy to understand.