Info about lcm programming for 2009 tandem snow plow

I am a municipal mechanic in Ontario, Canada. We have 2 2009 tandem snow plows with Viking snow equipment. Ever since we got them new nine years ago when the plow lamps were activated the high beams were flipped on the lights change to high beam but the indicator never worked. It works when the hood headlights are activated but not the plow lamps. Last week they both had to go in for a mandatory mto recall to correct the high beam indicator problem aswell as allow the marker lights to be on with out headlights being on with them.

We got the truck back and the plow lights and hood lights are on at same time. The plow lamps are stuck on low beam but the hood lights that are also on will flip high to low. There are also 3 active electrical codes that come up now that never did (short in rear left brake light, short in rear rt brake light, and a short in repeater code which I assume is the midship signal) brake lights and side signals are working.

The truck is factory wired for plow lights and by checking power at the factory plug at firewall that plugs into the plow light haress I should have 2 powers (left and right) but have only 2 low beams and 1 marker light power. The dealer replaced the 9pin plow harness connector that we supplied thinking this was issue. After a $700 dollar bill the gave the truck back to us and are not interested in correcting the issues claiming it has to be a electrical problem in harness not related to the program.

I am now responsible to make it work however I need. I don't understand how when all lights worked before the reprogram how they can claim its a electrical issue not related to the program. My question is has any one ran into similar issues, and is it possible to alter or inspect lcm info to correct the issue. I know how I can fix it if I have to and that is to unplug deutsch connectors at headlights and make a harness from them to feed my plow lights and eliminate the defective plow light circuit but would rather it be corrected properly.