Trying to determine bad harness or Rtek issue
 

Heres what i have so far, I can manually supply voltage and ground to the bar and it works properly, hooked up to the vehicle's harness it doesn't work at all. I checked for power and have supply power, when checking for ground I have a little over a volt on the ground side. I pin tested the each wire and made sure no shorts to any other wires were found and all grounds from the Rtek are solid. I don't have another computer around to swap out and was wondering if anyone else has had this issue?

I have an 1987 TII with a Rtek 2.1 that was built in 2014 and is just now being installed