pins layout on umbilical cord

Thank you guys
Think I got it

Take you Fluke and set it to read ohms. Put one of the test leads on a pin in your umbilical. Take the other test lead and touch it to one of the pins on the other end of the umbilical. You will either get a reading of 0 or 1. 0 is what you are looking for. That's the other end of the wire that you put the first test lead on. Make note of the pin location on both sides of the cable. Then move the first test lead to a different pin and repeat the process. Once you have all the pin locations accounted for, that’s the wiring diagram you'll need to make the cable.

A word of caution. If the person who's making the cable for you doesn't know to do this, you need to find someone else to make it. Or just do it yourself.

"So should i do it b/w two chassis or on the actual OEM umbilical cable?

Since you are having a "cable" made, you need to take the readings from the OEM cable itself. As long as it is the correct cable anyway.

You could also contact the preamp manufacturer and ask how it is wired.

Manufacturer wants to know how numbered male pins correspond to female receptacle, 1 to 1, 2 to 2,etc.
I don't think pictures would help him

Why not just email them photos?