As per PD tech service testing, I am to remove the two reverse polarity fuses and measure the converter input and the output to the battery.
Something is definitely wrong. The converter input is 18.65 volts. The output to the battery is 16.75. (EDIT: Should read input from the battery is 16.75.)
Voltage at the battery is 16.6.
I'm going to borrow my neighbor's high priced voltage meter tomorrow, my cheap meters cannot be correct. I've two low priced meters that measured basically identical numbers.
Still no LED, I'll check the harness continuity tomorrow as well.
Could be a faulty board?
Stay tuned.