Stuck under a load.Meritor Transmission will not go high

10 speed transmission on a 12.7 detroit.2003 Columbia.This problem started getting worse.First, I couldnt go in HIGH and then when I am highj , I couldnt go low.Now , all of a sudden I cannot go high.Drove about 15mph in 5th gear to a safe location.Ubered and replaced the whole shift knob which has the cruise etc on top.
It didnt fix it.Then I replaced the air solenoids and the piston at the back of the transmission(kit).Still didnt fix it.I cranked up the truck and checked the power going to the solenoids .When in High and Low.........No power getting to the solenoid.So I had a transmission guy come look at it.He said the harness was bad.He wants to change . all the harness and a bunch of all other BS like regulator valve , neutral switch and charge $750.I told him no, I only need the electrical part fixed.So, I went to freightliner and bought the 2 harness.I couldnt get the 3rd that goes to the ECM.I dont know what the transmission guys means , but he said the connector going to the ECM needs to be pinned.I havnt looked at it , but what does that mean?Another guys said the schematic for that may be proprietory.I am about to go under there tomorrow morning, but before I go and get this 3rd harness from Richard Kearns , I would like to know how to connect this harness to the ECM.This is definitely a power issue..Please advice

 

Meritor range shift solenoids , I already changed both . They are not getting power . Harness is the problem . I just need to know if I need all 3 harness or just the 2 that goes to this range solenoid

 

The transmission guy is on his way . $800 to run a power line to the harness and change the filter regulator. I have done most of the work . I just couldn't find the power source on the tranny . Down there has been rigged. If this mf dont come by 11 am tomorrow I will try to run a power from tje ignition and tie it into the harness I just purchased. I have done half of his job . Bottom plate _ removed, solenoids and shifter all changed smh . Not having a good day . I will be in it $1600

 

Fixed. The wires in the pipe shorted out . Not the shift knob that I purchased