2004 Pontiac GP. Had aux input installed with factory radio. Now gauges go to zero intermittently. Help?

Never had this problem before the aux input was installed. Im sure they used a kit of some sort with a wiring harness. When the problem occurs I get a chime and the Driver Info center says "Traction control Off" at first then it changes to "low fuel" because the gas gauge shows empty even though I have a full tank... Speedo is the only gauge that works during this event. If I drive it for a while the problem corrects itself OR if I turn the key to the start position momentarily the dash sort of "resets" itself and all is well. What gives. Please help. Never had this problem before the aux input was installed..???