How to: Make Oil pressure gauge perform like "real" gauge

Ok, cool. I'll definitely be doing this in a few months, because I can't stand seeing my needle drop like it is now. Thanks for all the help!

What would you consider an ideal oil pressure to be? I just installed a digital oil pressure gauge. It was a B!&%# and a half to get the sender installed but I managed. When the engine is cold at start up, the pressure reads somewhere in the 50's at idle. When driving it is in the 40's and 50's and when idling after everything is warmed up it drops to the high teens. Is that normal?

OK new question. What is part # E4ZZ 9278A for? I've been to Ford 3 times now and they still cant find that part. Is that # for a specific year, model or block size? I've now spent over $60 in wrong oil pressure switch's that I cant take back because they're electrical and you cant return them.

I need to know what vehicle, year, or block (2.9, 3.0) they came off so that the dealership can search it and find it hopefully. Maybe the dealerships here are a bit handicapped, I dunno.

The actual pressure switch is a neihoff part number of ff133e

The other part numbers on my box are...
Gen: OP24761
SMP: PS-60

I told them I wanted an oil pressure switch for a 1984 ford f-150 with a 300 inline 6..

a "real parts guy" will know what oil switch to use for fords with a real guage.. There are only 2 kinds.. 1 is only 1" across.. the other is 2"+ across.. the 1" one is a on/off switch.. the 2"+ one actually changes resistance as pressure changes (not just an on/off)..

Once you have the right pressure switch you just short out the resister on the back of your current gage (the 20 ohm one) and then all is well.

I need a couple more pictures then I can finish my article on converting the fake guage to a real guage.

~Mark

Thanks, that should help.

I just completed this mod on my 1997 V8. Click for my write up, step by step install, and photos.

Dead Link Removed

Scroll down to the oil pressure sender install post.

Bad news though. On my 1997 V8, the Dashboard did not have a real gauge in it. In mid 96, Ford's dashes finally caught up with the senders it seems. After putting in the new sender, the gauge reads exactly where it did before. It does not move. There is no 20 ohm resistor to bridge.

I may try looking in a junkyard for a cluster that has an old style gauge, or just getting an aftermarket gauge from Autometer.

Quick Poll: How many people have successfully done the mod on a late model (2nd gen) explorer?

Anyone know where this link with pics and how to can be found?

2000EB4x4inGA... I updated the think... But you may want to check your dashboard before doing the sender conversion - my 97 V8's dash was incompatible with the conversion.

How low does the gauge read?

I've read through the thread and am interested in getting a "real" oil press gauge. Could come in handy!

One question tho, I'm lazy and don't want to rip into the dash to short out the resistor. Soo, how low/slow does the oil gauge read if you just swap out the sender? Does it just register in the "low" part of the gauge or is it near some of the letters in "normal"?

Thanks for the info, guys!

It basically makes it so the oil pressure will read low.

Basically, the real sending unit (If I remember the numbers correctly) reads about 17 ohms at 60 psi... and at 40 ohm (I think) for 5psi (someone will need to check the actual numbers, but you get the idea)...

With the 20 ohm resister in the way, you will be at 37 ohms when your at 60psi and 60 ohms when you at 5psi.. This means it will always read low... e.g. max pressure will be around the center of the word normal.. which means at idle (with hot oil) will be near the bottom of the good range... (it is at the O area on my gauge with the resister out at idle when the 5w-30 oil is hot)

~Mark

Glad I read this. Since my oil guage sticks upon first startup till it gets warm. Sounds like I need to remove the sending unit and clean. BTW, my 1990 5.0 Mustang has an actual reading factory guage. I hate dummy guages, what a stupid idea.

Ok, I got impatient so I stole the sending unit off of my 84f150 w/300I6.. (I'll replace it with a pressure one again later) My gauge in the X now reads lower but I can not see any noticable difference if I rev the engine. I have not tried driving it yet but does this sound right since I haven't jumped the resistor or is my new(old) sending unit plugged up? Should the gauge be moving a lot or not now?
question2 How in the world to I unhook the speedo cable? I tried to push it further inside but it wouldn't go.. I think I can feel a tab but I'm not sure and theres no way I can see what I'm doing and I can't get the "tab" to unhook for me..?
question3 How does the check oil light on my 94 work? Does it come on when I lose pressure or what? Will this mod affect its working? If so how do I correct that?
question4 This is unrelated but I figure someone reading this post might be able to help with this as well. Since I have a 94 with no low fuel light, how could I add one to it? I wouldn't think it would be too hard to do but I know very little about resistors and etc.. Of course, this mod will have to wait till I get my gas gauge working again.. Thanks for any help and love the Forum!

Well, I'm not experianced with the 94, but I know starting in 95 the warning like for all 4 gauges was just simply the check gauge light, and it would come on if any of the 4 gauges were out of safe range. This serves as the low fuel light, the low oil pressure light, the low (or high) battery light, and the high temperature light.
I am not sure how to rig up your own light on a 94 for low fuel, and since no explorers had a single low fuel light, it may be difficult.
Good luck though

I'm sure it can be done... when the gauge drops to so many ohms it turns on the light.. but I don't know enough about resistors and stuff to figure it out off hand.. have to do some research I guess.. anyway.. to update my last post, once my oil warms up my gauge actually moves now.. jumped the resistor.. I found a sending unit for a gauge on my 94 on wrenchead.com.. debating whether to order it or just get one for the 84f150.. oh well..

The low oil light is measureing the oil height in the block.. not pressure.

To get the speedo cable out, you need to get your hand on the clips in the back.. and then "squeeze" the 2 sides.. it will then come apart.

If the sensor you put in from the 300 6cyl is a pressure switch (same as the X had) it won't move (it could read a little lower or higher).

If its a real pressure sending unit it will move when you change the rpms (when its cold it may stay high up until it warms up a little).

I think that was all the questions...

~Mark

Thanks I always wondered what the oil light was for there, never seen it come on yet.. (fortunatly..) I do have an actual pressure sensor.. I got a new one from advance yesterday but haven't had a chance to install it to see if its more accutrate. I got a little impatient on my last post, once I drove to work at the oil warmed up properly it did start to make a big difference. My only concern now is that my gauge doesn't go all the way down to low even when I first turn the key on with no pressure. (finally got the speedo cable off and jumped the resistor) I don't know if its from the old sending unit or just different voltages between this gauge and what the truck uses or what. I think I may add a T fitting and put the old sending unit on as well hooked to a light or something. I would like to add warning lights to my oil pressure and gas gauge and water temp but I don't know how exactly to go about it.. Can I jump off of the wires behind the dash through a resistor or anything and have it turn on a warning light at a certain ohm and higher/lower?

It is possible to have certain voltages @ the gauge trip warning lights, but it may not be worth the work it will take to do it safely (so you don't hurt the gauge cluster).

~Mark

Weatherman said:

Ok, finally got a real in dash guage for myself. Put the new sending unit on ($20) and tore into the instrument panel. There are 2 resistors on the back, big (physical size) too. One is on the top, one is on the bottom. If you look on the circuit sheet to the right and lower, you will see a resistance for each one, top being 20 ohm, the bottom being either 520 or 540 ohm, I can't recall which. Ayhow, you need the top one. I just took it out and soldered a new wire in it's place. The hardest part is just getting the speedo cable out, for me at least. If I had some pipe cleaner arms, it would be a lot easier.

New guage reads N at idle, R at 2000+ RPMs

-Ben

Click to expand...

confirm which resistor to "TAKE OUT" top or bottom???? thanks

Will this oil pressure sending unit fit a 2002 4.0 sohc.