Just did the moving oil pressure gauge mod today. Some of these instructions will be very specifically targeted to 302 engines. Yes, there have been several posts on this subject, and I have read them. Maybe my insight can make it go a little smoother for the next guy. Let's make something clear, though. This is a novelty mod. My gauge now moves between the "N" and the "O". It's definitely nothing exciting.

Start by removing the dash. You'll need a T20 Torx if I remember correctly. Take the gauge cluster out. Have fun with the speedometer cable if you have a '91 or older. There are other posts detailing that. Locate the 20 ohm resistor behind the oil gauge and solder a jumper wire across it. You could remove the resistor but I left it. Maybe someone will decide to put it back someday. Doesn't hurt anything to leave it.

<a href="http://www.flickr.com/photos/30418788@N03/7766178950/" title="photo 1 by dmeyer302, on Flickr"><img src="http://farm9.staticflickr.com/8299/7766178950_f70f19554f.jpg" width="500" height="375" alt="photo 1"></a>

Put the dash back together, you're done with that. It won't hurt anything to drive the truck right now if you don't have time to continue, but the gauge will read pegged out.

SIDENOTE: I put LEDs in at this step. For 4WD trucks with a tach, you'll need 5 360 degree white, 4 orange, 3 red, 2 green and 1 blue.

Plan on doing the remainder during an oil change. You'll need the extra space from the oil filter being out. The sending unit is between the oil filter and the power steering pump. Save yourself a trip to town and get a oil sending unit socket. It measures approximately 1-1/16", but it's a slightly special shape. No really, I'm not kidding. The $10 for the socket is not worth trying for an hour and THEN a trip to town for the socket.

Next you'll need a 3" piece of 1/4" pipe and an elbow. Yes, my picture shows a coupler but that's all I had at the time. Point the elbow DOWN and FORWARD. If I were you, I'd also grab a 4" pipe while you're at the store just incase.

<a href="http://www.flickr.com/photos/30418788@N03/7766174744/" title="photo 2 by dmeyer302, on Flickr"><img src="http://farm9.staticflickr.com/8423/7766174744_ffcc6c118d.jpg" width="375" height="500" alt="photo 2"></a>

Install NAPA part# OP6091SB onto the elbow. I requested the sending unit from an '85 302, and that's what they gave me. There will be a short or long pipe option, and this is the short one.

Almost done. Don't forget to finish your oil change. You'll need to splice and extend the oil pressure wire about 2-3". This isn't so terrible, you can pull the wire up from the top and work on it under the hood. Don't use butt splices, solder it like a good little boy. You'll thank yourself later.

That should get it. Now my gauge runs on the "n" at idle, and moves like a gauge is supposed to. Enjoy!

<a href="http://www.flickr.com/photos/30418788@N03/7766172698/" title="photo 3 by dmeyer302, on Flickr"><img src="http://farm9.staticflickr.com/8288/7766172698_dc419d19ce.jpg" width="500" height="375" alt="photo 3"></a>

 

hey before i do this just wondering. ive noticed that my needle just sits at the N all the time, doesnt matter if im idling or going 80 at 3k rpms it just always reads 'N' im getting oil to everything nd it doesnt ping or anything. a couple of people ive talked to say that just what it old fords do but idk just doesnt seem right.

 

That's because before you do this mod, you have a dummy gauge. It can only read at low or somewhere in the normal band. This mod replaces the switch and resistor (the stock sensor is a pressure switch) with a transmitter that varies current to the gauge, which causes the needle to move.

Not exactly accurate, but better than what it used to be.

 

So then after doing this mod does is read like a actual gauge or just a lil bit more of an idea of the pressures?

 

It'll mimick the movement of a mechanical gauge, and "should" track linearly across the pressure range.

In reality, it won't be as accurate as an aftermarket gauge (either mechanical or electric) because of a few reasons...

The first reason is that you're using a pressure transmitter that is meant to be an equivalent replacement part for the factory unit on engines so equipped, and as most enthusiasts will tell you, factory gauges (and their sensors) on any vehicle generally SUCK when it comes to accuracy.

Second reason is that aftermarket sensors generally have poor tolerances for repeatability, resolution, and accuracy. A Motorcraft sensor would probably do slightly better, but you're still only getting a gauge setup with "good enough for the average customer" quality.

The thought of replacing the cheapo pressure transmitter with an industrial unit set up for 4-20mA has crossed my mind more than once, but the gauge itself would need to be modified also.

 

Subscribing to this to make saving it more simple!

 

When I have done mine in the past, I just go to Ford and get the OP adaptor from an older 302 instead of making it out of pipe. It's a one-piece unit that comes out of the block and gives an angle at the end for the sender. Using that, I did not have to make my sender wire longer.

I would also like to point out that you do not remove the DASH to do this mod, just the instrument cluster. I would hate for a newby to drop his entire dash for this simple mod.

 

Also if you have a 1994 or newer your oil gauge is missing one coil. So you also have to replace the gauge innards in the cluster. I used the gauge innards out of a 1992 non tachometer cluster to make mine work right in my 1995 F-150 tachometer cluster. If you do not the gauge will only go half way up the scale.
The 1993 F-series tachometer cluster I put in my 1994 F53 also had all of the coils in the gauge and works right without replacing the innards.

This was already talked about in another thread in this forum with photos.

 

You guys are awesome, thanks for the info. Subscribed!