No, I dont have any kind of test equip of that sort. Here's what I found,in the red connector,I have a grn/blk wire in pin 20,a solid purple wire in pin 21, and a grn/wht wire in pin 50 that is labeled speedo. The speedo wire was left out of the harness intentionally for me to hook up.This wire-the grn/wht from pin 50 is the one I'm trying to hook up to the yellow and purple wires thats coming from c-100 in my truck's original wiring. Is this ok so far? Thanks for the help gag.