I made my oil pressure gauge a functional gauge!

The Oil Pressure gauge on ’88 and later trucks is an idiot light masquerading as gauge. In ’87 trucks the gauge worked was continuously variable, changing output as the pressure changed. After ’87 a binary on or off sender replaced the variable one. A 20 ohm resister was placed on the back of the gauge cluster to center the needle when on. The needle was always in the middle or all the way to the left. It told you that you had oil pressure on none.

I got an ’87 tach cluster to replace my ’89 non-tach cluster. That eliminated the resister. In 88 and later clusters that resister can be jumpered. I don’t know where it is on tach clusters. I can post a picture of my old non tach cluster, if wanted.

I replaced my o p sender with an ’87 sender. The ’87 sender is larger and will not fit between the engine and frame. I used a small 1/8“ npt 2” – 3” nipple coupler and elbow with hi temp Teflon tape to mount the sender. That was years ago and I do not remember the exact order of the pipe pieces.

This does not change the function of the ENGINE light logic, based on the value of the oil pressure and water temperature.

Good luck!

 

This does not work on 1995 and maybe 1994 clusters and newer trucks.
For them you would have change out the gauge guts with one from a 1992 or 1993 along with jumping out the resister.

For more information on the 1995 read the thread linked to below and pay attention to page #2.
https://www.ford-trucks.com/forums/1...-question.html

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I would just add a mechanical oil pressure gauge. Inexpensive and easy to do, plus it gives you an actual PSI reading.

 

+1, I have thought about doing this.

 

I was going to do this on mine. I had never heard of it being an issue with 94 or 95 and newer.

 

Read page #2 in the link I post above in post #2.

I did this mod on my stock Tachometer cluster in my 1995 F150 and the it acted like the mod was not done. I am going to replace the guts in the oil gauge and see if it fixes it when it gets warmer out.

 

I only know about '88 - '91 I don't know about the newer clusters. Sorry for any confusion.