Well, after posting this question I thought I would Google MBEC. Sure enough I got a hit on the diesel place site. Another common denominator was I had the parking brake applied. The first time the fuse was blown I was launching my boat and placed the parking brake on. The next time I was at the in-laws and put my parking brake on because of their steep driveway. The last time it blew I was launching my boat again. According to the diesel place post it could be.
<LI type=1>"MBEC 1" Maxi Fuse 50 Amp (SI Document ID # 1242532). If no shorts are located on circuit 642, inspect circuits 1340 after the "Rt Door" circuit breaker 25 amp and circuit 1440 after the "Seat" circuit breaker 30 Amp (SI Document ID # 1242687).
• Inspect circuit 1340 shorted to ground near the right I/P support bracket.
• Inspect circuit 1340 or 1440 shorted to ground on the support bracket for the I/P relay block.
• Inspect circuit 1440 shorted to ground under or in either front seat.
• Inspect circuit 1440 shorted to ground near the parking brake pedal assembly. The short may only occur if the parking brake pedal is depressed.
Here is a link to the post to give credit where credit was due.
http://dieselplace.com/forum/showthread.php?t=97150
I will check the wiring by the parking brake tomorrow.