look at this schematic on this page:
http://lt1swap.com/pictures/fig_7.gif
It appears that the gray (18ga) wire (circuit 120) from the fuse block (location F1/ connector C3) goes thru the relay on the fuse block and go straight to the pump.
here is the connector ref that I used to ID the wire:
http://lt1swap.com/underhoodfuseblock.htm
Hope this helps you out...