When installed backwards they peg at 5 (Actually like .25inch above, if not more). Anyway, it's because it's getting current/signal.
Basically, I'm saying electrical/ground issue. Check the wiring for exposure/cracks in shielding, etc.
Anyone happen to know what GROUNDS the oil pressure sender (instrument panel)? Mine is a little jumpy (new sender just installed), I'm 90% it's a ground issue.
