I have a Pontiac g6 2008 base, about a month ago my temperature gage would not move after I started my car, my ac was not blowing out cold air, but a few minutes later my cars ac kicked on and the temperature gage started working. It has been on and off ever since. Today my gas gage started moving up and down while idling, from 1/2 tank (which is how much gas I have) all the way to below e. It sounds like a wiring problem because it is so random as to when it happens and when it works again, but someone told me it could be my cluster? Where do I start??