I have a 2000 dodge p/u ram 1500 w/5.2 li. And 144000 miles. When I accellerate to the point of engaging passing gear the " check gauges" light comes on and the oil pressure drops to 0. When I shut the engine off for a few minutes the gauge works again. This truck has been in storage until recently and has a new battery. I have put about 300 miles on it since bringing out f storage. Any Ideas?