I tried that mod on my '97 Grand Marquis, it doesn't have a 20 ohm resistor on the back of the cluster. I happened to have an extra cluster, so I started experimenting with it. On the back of the cluster, the oil gauge has 3 terminals "B" "G" and "S" If you put 12 volts on B, and ground both G and S, the needle on the gauge goes to the midpoint on the scale. If this were a real gauge, the needle should have pegged at the high end of the scale.
I went as far as taking the gauge apart, thinking that the resistor was built into the gauge, if it's in there, it's under the windings for the gauge.
My guess is that the newer clusters will have the same fake gauge as my '97 has, and if that's the case, the mod won't work.
Edited by Timmn1 (11/13/07 11:01 PM)
Edit Reason: Spelling
1997 Grand Marquis GS - Died
Now have a 2003 Grand Marquis LS