GMC Repair: GMC Suburban Fuel Pump & Relay, fuel pump relay, jumper wire

Question
1997 GMC Suburban 5.7L 1500
Wouldn't start 3 days ago.  Had spark, so I checked the fuses and relays.  The relay clicked, but not consistently.  Pulled it and checked it with a meter -- didn't seem good.  So I jumped the 30 and 87 leads, heard the pump run, and it started!  Pulled the jumper wire and it kept running.  Drove to get and new relay, which worked.  Ran fine for a several short trips.

Yesterday it wouldn't start.  Fuses are all OK.  Seemed like the same problem, except the new relay seems fine, and the jumper wire between the 30 and 87 leads does NOT run the fuel pump.

My voltmeter shows 12V between the 87 lead and other grounds, but only 6V between the 87 and 30 lead.

Does that signal a bad fuel pump, or something else?  What should I test or fix next?

Answer
Richard

Sounds like a failed fuel pump,jumpering the 30 and 87 connection at the relay,bypasses the relay and sends voltage to the pump,the prime connector located near the relay does this same purpose if connected to positive battery voltage,86 should be ground,85 is ECM switched voltage,87 is voltage from fuse ECM B in the fuse box,87A is the prime connector,30 is the gray wire to the fuel pump,if the relay is commanded on during cranking you should have 12v at 30.


ED