My main concern isn't the aux fan. Without the original sensor hooked up it just runs the entire time, never shuts off at any temp range. I'm mostly worried about how the truck wants to stall when first started without the original sensor hooked up. Once it "warms up" it runs fine but i'm learning it takes 30 seconds to about 3 minutes befor the computer "regulates" itself. I really need to know how I can hook up the original and the new gauge so the computer proccesses the info from the original but i can have the new one to monitor the temp accuratey i can't depend on the dummy light alone. My truck was bone dry before that light even flickered and it got hot enough to burn off most of the oil and residue around the valve cover damn near looked like it was on fire. Know ideal how hot it really got because i had no actual temp gauge on till now.