92 GMC Yukon voltage/fuel pump problems

[Rock of Gilead]

I have a 92 GMC Yukon, and when it would crank up and run the voltage gauge fluctuated. Now it wont crank up at all. I thought it might be the fuel pump but I tested the fuel pump by taking a plug it from an old fuel pump cutting the ends off the wires and sticking it the battery. The pump runs perfect when attached to the battery, but it does seem to prime when the ignition is turned. Any ideas?

 

[tlamot01]

Having the same problem here. Truck runs fine when the oil pressure switch engages the fuel pump. Only primes about 10 percent of the time. Hoping someone here has figured this out or a way to bypass this faulty system.

 

[SunlitComet]

i have made my statements on this in the other thread.