02 CRV EX -won't shift from park

Hi, just bought a used CRV EX. The day i went to pick it up, it wouldn't shift from park. Owner took it to a mechanic he knew, and changed a blown fuse, it worked fine after that.

Today, 1 week later, I went to the car and it again was locked in park and wouldn't shift. I looked at the same fuse (located in the engine bay). it was blown again, so i changed it and the shifter worked again. the fuse is supposed to be a 15A fuse, but i put a 20A in there instead.

Any ideas on how to fix this??

thanks

What exactlly is that fuse for? Is it the hazard/brakelight fuse? I would check to see if there is a trailer hitch lite harness. Maybe its wired like crap and is shorting out every once and a while. Or you may have a bad brake lite switch down by the pedal.