Well I finally completed the swap and can answer my own question: C1-59 Yellow wire gets omitted because my 99 BCM has no Class 2 serial data input from the PCM in its original configuration, and I was able to successfully swap in an 02 instrument cluster without too much difficulty, hope this...
Jeff, the '02 0411, 5.3L and IPC into my 99 Denali L31 is well underway but I have questions:
On your instructions you say to omit/not use C1-59 YEL 710 Serial Data to BCM. If I go this route, will something not work correctly? Can I connect this circuit to Class 2 Serial Data on the DLC, BCM or...