Ok. I have a couple of problems, first the back up light on the trailer. It is out. Good ground, and wire has power on trailer side, as checked with a test light. Is this a warranty item? 2008 Model. Second, the battery compartment lights are not working. I checked the power wire and it has power. I also can touch the mercury switch with a test light and the test light will light up. Any ideas? I figured the mercury switch issue out by testing 2 other compartments the same way. If you have a compartment light string that is out, and touch the mercury switch with a test light, and the test light lights up, the mercury switch has no constant ground, therefore, it is a ground issue and the mercury switch is good.James