Well it works for sure. Towing last weekend to go camping I hit a pass that is 2K feet of gain in a few miles, multiple hairpin corners and max speed going up is limited to about 30-35 due to the corners. Well it was 95* out, with a 15mph tail wind. So there was plenty of power/heat being made, but not much cooling effect from fwd movement... Fan came on to what I am guess 100%, it makes noise and works great. First time I have heard it in 50K miles!