I finally got around to installing the harness in my first conversion attempt. I believe I have installed everything correctly based on Eagle Marks writeup and available wiring diagrams.

I used a 12v terminal block from my battery with fused lines from the terminal block to both the power and fuel pump relays. When I connect the terminal block to the battery, I can hear both relays momentarily "click".

Now, when I turn the key to "on" my fuel pump will not cycle. I've checked for power at the fuel pump/sending unit connection harness (new 87 GM model tank and sending unit/pump) and there is none. I then checked for power at the supply line coming out of the fuel pump relay and there is none. It's my understanding there should be power to this wire for a couple seconds while the system cycles the fuel pump. So I think its an issue related to my fuel pump relay.

Here's how I wired the factory fuel pump relay (from 91 Chevy donor truck):

Orange - 12v fused input from battery, also connected to ECM B1/C16
Black/White - system ground
Red - to fuel pump
Green/white - to ECM A1
Grey - to ECM B2

Wiring diagrams I have referred to says ECM B2 should be tan/white, but my ECM B2 was solid grey.

What I'm still confused on is the wiring diagram shows ECM B2 connected to the fuel pump relay and then on to the pump. If that is the case then what do I wire the fuel pump relay red wire to? I cannot find a wiring diagram for the 1991 fuel pump relay. The build threads I have read only reference four wires for the fuel pump relay. I didn't take good enough notes when disassembling the stock harness on this particular item.

And lastly, when I turn the key to "on" my SEL flashes 7 times and then turns off. It does not stay on when the key is on. I verified that it is wired to a circuit that has power with key "on" but not crank.