2007 RAM 3500 Engine Problems

Check engine light has gone on intermittently. Have had it checked with no reason for the code. No sign that it was the engine harness. Contacted dealership and they explained they couldn't look at it for 3 weeks. Brought it to another mechanic and replaced computer. a week later it damaged that computer. I called dealership and they again advised there wad no way to have it towed in for at least 3 weeks. Only 1 diesel mechanic present. Had diagnostics run again and was diagnosed as engine wiring harness. Engine wire harness has damaged 5 computers. While driving vehicle, it suddenly cuts off, with warning lights on, power steering will not work. There is no warning to this happening. It has happened several times on the road, but would restart while still rolling. Now, there are no replacement wiring harness available to purchase. This is only a 2007.