I attached the wiring schematic below for the power windows and locks below. You should be able to determine which pin to check based on the wire's color.
Pics 1 and 2 are the windows and pics 3 and 4 are the locks. Note that I had to cut each schematic in half to make it readable. I did overlap them so you can follow from one to the next.
As far as the pinouts, I attached the C1 and C3. For some reason, I don't have the C2.
Note: This information is for a 2003 K2500. If you need additional information for the 2002, I need you to start a new thread. We try to keep the threads specific to one vehicle/problem so that it helps others. I hope you understand.
Just copy and paste your question requesting info for the different year.
Here is the link to start a new thread:
Also, I went with the K2500 because the engine size isn't offered in the 1/2 ton truck. I made the assumption it was a 3/4 ton. Let me know if that is correct.
Here is a link that you may find helpful:
I hope I got the right info for you. Let me know if it helps.
See pics below.
Images (Click to enlarge)
Wednesday, August 18th, 2021 AT 8:33 PM