Also something just came to me.....do you have a fully charged battery? If you have anything under 10 volts, that *could* hinder the operation of the ECM. You need over 10 volts. I would first be looking at this first.
If that checks out, then I read on.
I would start by pulling the harness from the back, you checked at the connector, but did you try probing it before the connector at the back? How about at the relay, are you getting 12 volts at the relay, both before and after the relay? If your getting 12 volts at the realy, then the problem lies somwhere between the relay and the wiring to the pump. If your not getting 12 volts at the relay, then you have a problem before the relay. If this is the case, then you'll have to trace wiring from the fuel pump relay to the fuel pump fuse connections, under the dashboard.