I assume you narrowed it down to the passenger-side lamp by having a good fuse installed, removing that lamp only, and turning them on, and your fuse does not blow. I'm also assuming you keep blowing the same fuse. If this is not the case, please elaborate on how you came to the conclusion of which one is blowing the fuse.
When it did blow, was it immediately upon turning on the lights?
When did it first start to happen? Did you have the passenger side lamp burn out, you replaced it, turned on the switch, and fuse blew? If so, have you put a multimeter on the new bulb to see its impedance? Have you tried removing the bulb from the driver side and installing in the passenger side, install a good fuse, and see if it still fails?