dealership said the truck needs a $4K unavailable in cab harness

hey, people you are the best of the best. 2005 379 C13, Truck was presenting as a fuel delivery issue. Unburned fuel, white smoke no acceleration. Brought the truck to an independent mechanic, to put it on his computer. All soft fuel lines and tank cross over was replaced. Fuel filter nearest fire wall wasn't filling with fuel. changed engine wiring harness, ECM, injector harnesses, and injectors. Mechanic said needs in cab wiring harness, Had it 3 months, will not exceed 1200 RPMS. Harness deemed obsolete at dealership. Towed to Peterbilt. Changed fuel pump, replaced the aftermarket injectors that weren't working, went with DELPHI, got injectors to work. No longer puking out white smoke. Still no acceleration. Service manager said when he lifts the wiring harness coming out of the cab, the truck runs smooth with acceleration. He said it too was the in cab harness. I told them Peterbilt didn't carry it, it was obsolete. He said who told you that, I responded your parts guys did. He wants to just to locate the broken wires and splice them. ANY IDEA WHICH WIRE?WIRES control acceleration? I got $25k into the repair at both shops. Thanks

 

Thank you

 

Thank you

 

I guess I could call them and see if they carry that harness. I know in the past, for most questions dealing with parts for the actual chassis, they refer me to Peterbilt