1993 Chevrolet S-10

Electrical problem
1993 Chevy S-10 6 cyl Four Wheel Drive Automatic 112k miles

fuel pump quit, or so I thought. Aftter replacing fuel pump and before reinstalling gas tank, I applied 12 volts to pump and heard it run. Then I checked again after I plugged the electrical connection together under the truck and turned on the ign but pump did not run. I unplugged connection and I do not have 12vdc at the plug. Fuse is good. I believe the fuse is labeled ECMB. I looked at a wiring diagram in a repair manuel and it said to check the fuel pump relay and the oil pressure switch. I cannot find either. Where are they located and what do they look like? Are we talking about the oil pressure sending unit that works the oil pressure gauge or lite:
Dewayne grubaugh
March 17, 2008.

All you got is 2secs to look for power at the gray wire anything over 2 sec you ain't gonna have it the fuel pump relay de-energizes which is controlled by the computer-When the engine fires up the oil pressure sending unit powers the pump see below-

Mar 17, 2008.