I started my truck last night to go shut my generator down in my RV. When I turned the key to the "on" position to wait for the heat cycle. While waiting and shortly after turning the key to the "on" postion all of the gauge needles jumped to about half or three quarters of their postion and returned to normal. I thought to myself that it was a self check that I could get my 01' Jeep Wrangler to do if I followed a certain procedure. I was unable to duplicate this. My question is how did I manage to do this. Thanks.