Fuel Pump issues with Silverado

I put a new fuel pump in a 1999 Silverado 5.3 ltr 4x4, before doing this I was able to turn the key to the aux position and wait for the fuel pump to stop and then proceed turning on the truck and it started on the first crank, now after putting in the new pump - I turn the key to the aux position and when it stops I proceed turning on the truck and it just cranks over and over and over, I turn the key off and turn it back on to the aux position until the pump stops again and proceed to turn on the truck and it starts on right up on the first crank? Any ideas why it does this now?Thanks