I have a 91 S10. I jump started my daughter's car and it went dead. I was not getting any fuel from the tank. I ended up replacing the fuel pump and relay and the fuse. This did not fix the issue. Discovered the injectors did not have power. Ended up replacing the computer. Now injectors have power but the fuel pump will still not run. Had the alternator tested and it found to have a bad regulator so I replaced that. I replaced the ignition module. Today I discovered the headlights don't work. I removed and cleaned battery ground on both ends. Also cleaned the headlight ground and fuel pump ground. I took a voltage reading at the connector to the fuel pump. I got a reading of 8.5 volts and it is constant. The pump will run if I run directly off the battery. The truck will run if I pour fuel in the throttle body. What else should I check and or try?