Thank you for forwarding me the link regarding the harness. However, I cannot see the end of either harness to see if it has male and 20 pin and 16 pin connector. I believe there must have been a limited number of trucks made like mine because all of the harness I have found are wired for NAVSTAR, stereo steering wheel controls or set up for a Bose system which mine has neither. I only have the basic OME stereo & I only have cruise control to my steering wheel, therefore I have no need for the CS-GM31L interface.
This has been a huge pain in the neck for something that seems should be so simple to find.