Ok, on the passenger side, this harness has two wires coming out the front end of the harness. One is yellow, one is puple. The yellow one splits and has two female insulated spades about 7 inches apart. The purple one has one insulated female spade. When I say insulated, I mean the "wrapped in plastic with the little lock/catch doohicky!"
Progressing toward the firewall, you find the plugs for the 4 passenger side glow plugs. Then, towards the center of the harness, which would be installed at the rear of the engine, there is a plug that has the purple and yellow wires running to it, sticks out of the harness about 4 inches (I am guessing that this goes to a temp sensor to activate the fuel heater and fast idle, but I don't know for sure). Then, about 6 or 7 inches toward the driver side, there are two big blue wires that go to a ring terminal, these are the glow plug power feeds. There is also a purple wire with the round Delco type plug (round with a latch, has a male pin inside). From there, the harness goes back forward and has the four glow plug - plug ends.
The harness I have is International part number 1807648C94 -
Here is a picture of it.
Hope that helps - let me know if you want to know anything else about it. I brought it in from my workshop, so it is here on my desk for a day or so!!!