Daughter has a 1995 chev blazer 4x4 i have a problem getting fuel pump to activate.Ive checked relay replaced fuel pump computer borrowed a ignition module in case that was in circuit no luck. I can put power to fuel pump at pigtail at tank engine runs. ive traced all wires to computer to relay back to tank to check broken wire. on wiring diagram we found all wires where they go to and from except a back and white wire diagram showed us at relay but did not show where wire goes to other than relay. that is the only wire i could not find where it goes to from relay. the middle leg of the 3 pin side other side of relay has 2 pins. 4 out of 5 wires at relay go back to the computer. seems what i am lacking is white black wire must be the switching leg at relay that throws 12 volts back to my gray fuel pump feed wire at rear of vehicle. does anyon know any info that can help us thank you

 

At the relay:

Grey wire goes directly to the fuel pump.

Red wire, (pump prime test terminal) is connected to the grey wire inside the relay, only when the ignition is in the OFF position. If you apply battery voltage to the red wire, (ignition OFF) the pump must run.

Orange wire must have battery voltage at all times.

Black with white trace wire goes to ground. It must show less than 5 ohms resistance to ground at all times.

Green with white trace wire must have battery voltage for ~2 seconds, (then drop to zero) when the ignition is initially turned to the RUN position. It must have battery voltage constantly when the ignition is in the START position, and while the engine is running.