Hello the other day I noticed my sensor which is mounted on back of license plate bracket fello down and was dragging the ground. It used to read right on before sometimes a little warmer on 90+ degree days I attributed this to the black roadway where as now it is constantly giving me a reading about 10 degrees cooler then actual temp. Do I need another sensor seems they cost about $100 any one have a used one laying around for my 85 300sd?