If your discription of the relay contacts is correct wire it thisa way.
Gray wire coming up from the OPS goes to, D, the coil, F, the other side of the coil, goes to ground. The other end of the gray wire coming out of the engine harness goes to, E the common of the relay. Terminal, A, is spliced into the orange wire going to the OPS. This keeps Fuse 11, the original fuse for the lift pump, as the fuse operating the pump.
Do not connect, C, to anything as it will have voltage on it during the glow plug cycle and will short out and most likely cause a fire. Depending on were you mount the relay you may want to insulate the terminal for safty.