Anyone know what might be the problem with my stock FD oil pressure gauge. I put a mechanical gauge on the LS,and it ead 45#.  I tun the key on and breifly touched the O.P. wire to ground and the gauge jumped all the way up. I checked the sender by hooking it up to my compressor with 20# of air and with an olhm meter on it,I gradually increased the air and the olhm meter gradually moved with the air.  The gauge will not move with the wire hooked to it? I would appreciate any replys.  kenscar33ls.