One of my 2001 GTX RFI's started blowing the 5A Fuse on the MPEM. After replacing the entire unit with a used one I decided to try and find the problem with the original. After opening the MPEM and spending a few hours of carefully scrapping out and removing the black rubber stuff, the circuit board was able to be removed from the housing. Another hour of carefully scrapping some of the same black stuff from the board revealed an Automotive Transient Suppressor Diode (MR2535) that was shorted to ground causing the fuse to blow. The component is located very near to the fuse location (See attached pic). The replacement part was ordered online for about $4 + shipping along with some circuit board potting compound (the black rubber stuff). Once the diode was replaced the unit was tested and worked fine. The board was placed back into the housing and was re-potted. It is now in the watercraft and has been working fine all season. Hopefully this post will help some of the do-it- yourselfers save a few $$ if you have the same problem.