Nissan Repair: 99 frontier gauges, fuel gauge, aftermarket stereo

Question
when my truck is running my gauges work fine,but when I shut it off the fuel gauge goes to full and the water temp. goes to hot and then bounces.Which is draining my battery if I don't start it everyday.Can you tell me what the problem sounds like to you.Thanks

Answer
Darrin,

I would check the ignition switch to make sure that is it fully off and not leaving power to the gauges.  If you have an aftermarket stereo or alarm make sure that they are not hooked to one of the wires that shows to be ground when the key is off and hot when the key is on.  Nissan likes to use isolated grounds.  So, if there is an amp, stereo or alarm that has been installed recently that could be the source of the problem.