A long time ago, in a galaxy far, far, away - OK, a State a few hundred miles from here. I had a problem with the (yes THE) fuse in my SL350 blowing without being able to figure out why. Skipping to the last page of the saga, it turned out that lead to the brake light ran in a channel built into the rear fender and the insulation chafed through within that channel. When I hid the brakes and the wire bounced against that fender at the same time the fuse would blow and the bike shut down. A summary of the intervening chapters involves a field replacement of the fuse with a piece of random wire found on the side of the road and a melting of both brake light switches.
The moral? I would trace the wiring between this fuse and the pump and be sure nothing is amiss with that wiring.