I have a 1990 chevy 3500 with a 454. When I hook up the battery terminal, I can hear the fuel pump running in the tank, with no key in the ignition.. I have dual tanks and when I switch the tanks, the fuel pump also switches to the tank I have selected. Also ,the oil pressure gauge no longer works ,,it shows all the way to the right (pegged out). It seems to me ,they happened at the same time, but I am not sure the y are related.The truck starts and runs fine but will discharge the battery quickly when not running because the fuel pump keeps running.What electrical problem could make this happen?????

 

check your fuses. also, were you working on the truck?