By-pass wiring Harnes for Cooling Fans

I am trying to solve an overheating problem where my cooling fans will not come on unless my AC is on. I had the same problem on my 1999 3.8 buick engine I fixed that problem by buying a wiring harness that plugged into the wiring harness of the fans. It was plug and play. I understand the racing guys were using this harness to cool their engines between drag races.

I bought this harness from a guy on Kijiji years ago now I need another Does anyone know the company that makes these units

Why not fix the problem, the fans should come on at 222 degrees, if not the pcm is not telling the fan relay to turn on, a full scan can trace problem assuming it is just not a bad realay or wiring.