Review on Derale 16759 Adjustable Fan Controller by John Benjamin

I installed it on our 2007 Uplander in early summer along with an additional transmission cooler with fan. We wanted to tow a U-Haul 6x12 trailer from Orlando to Oklahoma City via Houston. It was easy to install and set up, worked flawlessly when we moved, and also had the added benefit of lowering our engine temp (we were loaded with 9,740 pounds). So why am I giving it such a low rating? It got hot again (of course) and we wanted to cross the Rocky Mountains, but the fan wouldn't come on at all. I had to troubleshoot - the sensor failed, which meant the only way to turn it on or off was to install or remove a jumper from the sensor pins on the controller. I am planning to install another sensor from another source.