GM-GMC: my van quit, fuel pump relay, jumper wire

Question
I have an 1987 gmc2500 van with a 5.0l engine. The van was loosing power on acceleration so I changed the fuel filter. When I tryed to start it it would crank but not start. I didnt hear the fuel pump relay or hear te pump in the tanl come on. I checked the computer codes and found a code 12(normal) and a code 44(lean). There is no signal 12v fuel pump coming from the ecm but there is 12v from the fuse panel. Can i measure the fuel pump continuity from the relay plug, and can I manually run the fuel pump from the test plug on the relay connector.  

Answer
Glenn,
 
   First things first......do you have a good wiring diagram for the fuel pump/relay system? Basicly you'll have a constant power, probably from a fuse a constant ground and a switching power controlled by a PCM/ECM ground. Most of the PCM/ECM will actuate relay with a ground very rare for a power to be used. Especially on GMs. you can measure resistance from the relay plug to the fuel pump plug but both must be unplugged. Use on Ohm meter with you lead on the relay plug and the other lead on the fuel pump end. It's a good quick idea to jump 12V to the pump by bypassing the relay just use a jumper wire to feed 12V from your constant power to your fuel pump terminal in the relay plug. All of these tests are really redundant if the relay does not "Click" when you a.) turn on the key for 5-10 seconds then "click" off and then again "Click" when you turn and hold the ignition switch in "crank". If it does not "click" then you have a relay or a actuation problem and the pump and wirring are probably OK. Let me know how you make out with this!