Chevrolet Repair: 2002 chevy express van fuel pump

Question
Hi Tom,
I have replaced the fuel pump & filter in my van after it would not start and the pump wasn't running when I turned the key. The pump still doesn't run but when I put power straight to leads on the pigtail to the pump (grey & black) the pump turns on. I checked the fuse and the relay and they are good. (The old fuel pump was in fact bad so that was the original problem).  Could the fuel pump going bad have shorted something else out?

Answer
HI CARY,,, SO YOU ARE SAYING THAT WHEN YOU POWER UP THE FUEL PUMP RELAY FROM THE UNDER HOOD AREA,YOU HAVE POWER [12 VOLTS] TO THE GREY POWER FEED WIRE GOING TO THE FUEL PUMP UNDER THE TRUCK  AT THE HARNESS CONNECTION ??? YOU ARE HOT WIRING THIS ON TOP OF THE SENDING UNIT ??? IF THIS IS THE CASE THE WIRING HARNESS GOING ON TOP OFF THE TANK SENDING UNIT IS MORE THEN LIKELY BAD....THEY HAVE HAD A LOT OF PROBLEMS WITH THE WIRING HARNESS GOING TO THE TOP OFF THE SENDING UNIT. CORRODED CIRCUITS.] DID YOU REPLACE THIS WITH A GM MODULE OR AFTERMAKET ?? IF IT WAS A GM YOU SHOULD OF GOT THE SENDING UNIT WITH THE PUMP...IF AFTERMARKET YOU JUST REPLACED THE PUMP,, CORRECT....CK THESE CONNECTIONS VERY CAREFULLY...LET ME KNOW HOW THIS GOES AND GOOD LUCK TO YOU,,,TOM..