[HUMTECH]

To test the compressor you could put power to the red wire and ground on the black to see if compressor runs. That will be in the 3 wire connector on the compressor(third wire will be yellow thats the overtemp signal wire) But if it does come on does not mean it still makes enough volume to fill the bags, compressor could be weak. Did it come on at all in the truck? Did you test the relay that is inside the left front of framerail approx below the brake booster? Relays were common failures due to the close proximity to the exhaust manifold. As for the module no real way to test it without scan tool.