Hey Powel, since you just replaced the tank if you used one with a switch it should be o.k. The signal is just a ground return (bk/wh on one side of the NO switch and the return is lt gn) it goes back to the a/c controller of all things, go figure. The return signal goes to pin 14 on the j2 black plug. The only thing I can figure is GM did it to shut down the a/c in a low water condition via hard wire, but it doesn't exist on the gas engine. Seems odd to me.