Omni fuel problem

[yamaha51]

Rescued a `89 omni and it has no fuel pressure. I pulled the plug on the fuel pump and I have no voltage.Checked the fuse and it`s ok.It has 3 wires going to the pump 1 white and 2 colored wires, I belive the white is the ground.I pulled the fuel pump fuse and probed it with a test light. When I turn on the key I get full power for about 1 second and then something under the dash or hood clicks and the power goes off. It does this with the pump plugged in or not, same thing. The fuse is not in when I tested it so no power would have gone out to the pump or wires to the pump.Any ideas on whats going on???? or things I can check??? I would hook up a jumper to the pump but I don`t know which wires since there are 3. There is not much gas in the tank but I didn`t think that would shut off the power to the pump???ANY HELP WOULD BE WELCOME!!!!!

THANKS STEVE

[charger R/T]

the pump only runs for about one second to prime the system and shuts off. that is normal. Once the engine is cranked and the computer sees a signal from the HEP it will turn the pump on all the time. Re-do the test and have some one crank the engine.

3 wires
if the fuel pump also has the fuel gauge unit on it that is the 3 wire. My daytona has 2 holes in the tank one for fuel pump and one for fuel gauge. Most cars use just one hole and put the fuel gauge unit on the side of the pump. I don't know what an Omni uses I have never worked on one.
Tim