[fredmo1947]

I had the same problem with my 911S, gauge pegged when the key was on the "on" position.
Checked all wires for shorts, no problem. Installed another gauge I had available, same situation with gauge pegging upon turning key to on position. Bit the bullet and bought a $70+ oil sending unit from our friends at Pelecan....problem solved. PS: got a used combo oil temp/pressure gauge for sale $60 + shipping. (I'd spend the money on a sending unit first!)