47-55.1 Elecrtical?

[J48chevy]

Well first the good. Started my truck for the first time and success it runs great. The bad, electrical. Here is my dilemma. I have the American Autowire harness I installed. I am running the dolphin/shark manual gauges. When I turn the truck on my gauges are on. I have tried everything I can think of but after 3 hours and same issue I took a break. The back of the gauge with volts/fuel/temp/oil there is a harness with a black, yellow, red, white, blue, green. I know the green is oil, blue is fuel, white is temp, black is ground. The red is + and yellow is + (light switch). This is what manual says. So if this is right I hook the red to 12v fused source and the yellow to???

My speedo gauge just has the 2 wires for the bulbs, red/black. When I hook the grey wire from American Autowire harness that says dash light clearly on the wire to the red wires, and the black to ground, the lights stay on.

As I am not a wiring guru, I have followed all instructions but this one has me perplexed. Any thoughts and ideas would be appreciated.