Today, I began to check for continuity along the entire path of the pilot mic PTT wiring. I began by removing the radio select switch and checking upstream to the radios -- all good. The problem was downstream toward the intercom or the PTT or mic receptacle. So, I pulled the intercom and removed the DSUB connector. I was able to isolate it to Pin 12 which was the wiring to the pilot PTT or mic receptacle. More tomorrow.
