I installed a water temp. gauge in my car. The problem is I can't get the stock gauge to work as well. The water temp. sender screwed right into the b18a head were the factory one was. I hooked both of the gauges sender wires to the autometer sender and both gauges wouldn't work. I took the factory wire off and the autometer gauge works. How do i get both the gauges to work together. Can anyone help.