On K5 Blazers, there is a relay/fuse mounted on the firewall, mine was clearly marked. But, it was the fuel pump.
Drop the tank (hope it is not full, mine was) and remove the pump, float assy. I used a floor jack to help hold the tank while I disconnected the mounting bands, and to lower/re-install. Replace in reverse. Other than time consuming, and I had to remove most of the fuel to make installation easier, it wasn't hard.
Another consideration, the fuel pump quit on my 98 Silverado, when I went to the dealer to get a new pump, they told me they gave a lifetime warranty on pump & labor. Sooo, I took the truck to them, had them do the work, approx $460, with lifetime warranty. Don't know if this is GM warranty, or just this dealer. (failed to ask)
FWIW
