Panda,
I am assuming in this post that you are going to use the cable from a Q500 compass to make the new wiring harness. You will need to remove one wire completely from the “4” Pin connectors, and relocate one of the remaining wires at the slide mount end. You will also have to remove one “Hole” from the Slide Mount end. It’s easier for me to just remove all wires from both ends, remove the hole, do the wiring and soldering, then use the numbers to make up the junction beside the gimbal Plug connector, and to land the pins in the right places on the final connectors. Doing them ONE WIRE AT A TIME might be easier to avoid getting crossed up.
Here is how to slip the wire pins out of the connectors:
Use something with a sharp tip to bend up each Pin Latch:
Gently tug the wire from the rear to remove the Pin:
When all pins are out, trim the end hole from ONE of the connectors. Cut down THROUGH the end Hole (doesn’t matter which end). Then trim the connector up as needed to fit into the Slide Mount “3 pin” connector.
These pictures use the numbering pattern from Steve Carr’s post above. I added the original colors, but you are going to be using wires that are all the same. Just match the numbers at each point.
I just thought of something. The picture of the green mainboard above is the standard version that came with a factory Q500 4K. Unfortunately there were several other versions floating around at the same time. The arrangement of the holes where the PWM attaches to the left rear of the mainboard varied A LOT. Some boards had more rows of holes, some used a slide-on connector, some had a soldered on "box" connector, etc. The PWM is always one of the INSIDE holes. IF your board is not standard, pay attention to which "row" is associated with the original PWM connection. Getting the wrong "Row" won't damage anything ( but the camera may not initialize and you will not have manual tilt, until you find the right "row"). Getting the wrong "column" WILL damage things.
Please question everything, and feel free to ask anything that is not clear. As you know, this was patched together quickly, and hasn't been reviewed by anyone. I will be here for about another hour or so, and will check the post before I turn in for the night.