Help! Fan keeps coming on

had the fan hub replaced a short while back. as of now. the truck is fine. fan is working & I had to put a new/used water temp gauge in. so it appeared to be a loose or, or wire gounding out between solenoid & water temp sensor. the shop may have shorted gauge out when testing & probing the wire, cause gauge worked before, got one for $ 10.00 & all seems to work. I wish I had more of an explanation, of what the actual cause was, instead of speculation. thank you to all who spent time thinking & helping me on this.