Stop in for a cup of coffee

I think I am a dumb ***. Messing with straightening out wiring and slapping a cheap elect oil gauge in the truck. So get everything ran and check the guauge. It swings to full as soon as I hook power to it. Messed with that for a hour. Had to walk away. Hey dont the cheap ones do that when they first get power? Just did the touch power thing to check it. Went right to 100 psi not running. I HAD A DREAM!