Fuse. Keeps blowing out on the on. Position

Something is shorting out causing the fuse to blow. You need to find where electricity is able to short to ground (metal body part) or to the other wire in circuit. Without more specific information there is no further way to know what might be going wrong. Is it a light circuit? A motor circuit? Have to do with engine, and ECU? OR interior and lighting?

check you ignition switch wiring, or loose wire to terminal will cause enough heat to blow fuse. What rating fuse is suposed to be there? Make sure to use only the number fuse they specify, or if it's a junker and you don't really car if problem gets worse, you can try to jump the fuse contacts with aluminum foil, I would go a few amps higher on.fuses first. This can help get you home if your stranded on a boat, or car or vehicle and you find a lost, broken, or blown fuse Sometimes it's a one time thing, and if an Emergency (a real emergency) then try the jump terminals trick. Saved me and my family from Being stuck at night, on an out going tide near asatigue island. If not for candied cherry wrapper used to complete starting circuit, we would have been swept out to sea with no power or lights in a 14ft turnabout. Just know what you may be.sacrificing when you do so as well as be ready for.possible fire, so.have way to put it out if so.