Oil Pressure send issues

[Custom Sills]

Needle of the oil pressure gauge is always at the bottom. Changed the sender already but still.

How is the wiring of this system? There is one cable on the sender
Does this cable go directly to gauge in the dash? Which cable color have the oil pressure sender in the dash?

I need advice please

 

[RAU03MACH]

even if you move the wire around it does not rise.
that wire does go to the back of the cluster dash

to be on a safe side i would get a mechanical gauge and hook it up where the sender is just for test

 

[cobrajeff96]

It's a single wire, red/white I think.

 

[maillemaker]

Following...mine pegs low when engine is hot.

 

[cobrajeff96]

Well, actually that's not abnormal. When engine is fully at op temp, the oil has reached the upper end of its 'thinning' and thus will loose pressure. It's actually not a bad thing, it just means the entire motor is at equilibrium. On cold start is when you will see the most pressure the system will ever have because oil is thicker.

I have a mechanical gauge on the yote motor and it makes loads of pressure on c/s, something like 80 - 90 psi. After a long drive it'll actually read zero!

 

[Custom Sills]

It's a single wire, red/white I think.

Does this wire go from the sender directly to the gauge in the dash?

even if you move the wire around it does not rise.
that wire does go to the back of the cluster dash

to be on a safe side i would get a mechanical gauge and hook it up where the sender is just for test

The single wire from the sensor goes directly to the dash did I understood right?

An analoge gauge will surely helo to eliminate the problem. But to have a cleaner dash I want to fix the original

 

[cobrajeff96]

The oil pressure circuit in the SN95 was never meant to be accurate, anyways. It's more of a 6psi switch rather than a sweeping gauge. Ford determined if you has at least that amount of pressure, things were ok inside the engine.

There is a way to make the oil pressure gauge accurate and sweep across a range. Mark Olson at accutach.com figured this out and made it public. I've purchased all the materials to make it happen in my car, but haven't done the work yet (and it's not bad).

His procedure replaces the OEM 6psi switch and uses a true pressure sender (rather than a switch).

But the red/white wire should go direct to the gauge cluster, I don't think it passes through the ECU.

 

[Custom Sills]

(the red/white wire should go direct to the gauge cluster, I don't think it passes through the ECU.

I fixed it by using a new wire frim the sensor through the firewall to the gauge white/red wire. The back of the cluster shows also names of each connector.


Thanks for the support and hint for the white/red cable. The gauge works like charm now

 

[cobrajeff96]

So then what was the original problem? Was the factory wire cut somewhere?

 

[96blak54]

WOW Great troubleshooting! But im with cobrajeff96, what did you find and what did you do to correct the issue?

 

[Custom Sills]

So then what was the original problem? Was the factory wire cut somewhere?

WOW Great troubleshooting! But im with cobrajeff96, what did you find and what did you do to correct the issue?

It seem the original wire was cut somewhere or maybe the connector at the sender is faulty. I just did not wanted to waste my time, thats why I routed a new wire which one I locked at the sender with a washer and M5 nut, because I had not crimp connector. BTW I cutted the original white/red wire at the dash fully of to do not have any possibly shortcuts with the old wire.

 

[cobrajeff96]

Yea, that 90* rubber boot connector going to the terminal is not strong.

 

[PNW Mike]

The oil pressure circuit in the SN95 was never meant to be accurate, anyways. It's more of a 6psi switch rather than a sweeping gauge. Ford determined if you has at least that amount of pressure, things were ok inside the engine.

There is a way to make the oil pressure gauge accurate and sweep across a range. Mark Olson at accutach.com figured this out and made it public. I've purchased all the materials to make it happen in my car, but haven't done the work yet (and it's not bad).

His procedure replaces the OEM 6psi switch and uses a true pressure sender (rather than a switch).

The OEM oil pressure "gauge" isn't really a gauge, it's an "idiot light" cleverly disguised as a gauge.

I wasn't aware of the accutach.com kits, but I did the same basic conversion on my '97 GT using a MeterMatch (technoversions.com) and it works great. It was a bit involved, but very much worth it to see what the actual oil pressure is, not that it's "over 6PSI".

I was also able to hook up the unused "oil" light in the '97 gauge to the warning light feature on the MeterMatch so that it flashes if I have low oil pressure, which is great if something goes sideways - I have a chance to shut down to try and save what's left of the motor. IIRC, that light was used for the low oil level sensor on the first year or two of the older 302-based 5.0L SN95's. It was present in the cluster and unused on my '97 with a 4.6L, so I used a scavenged terminal from a parts cluster connector + (IIRC) a new bulb to hook it up, and it works very well and looks factory. I kinda wish there was an easy way to make the earning light not blink, but that's how the MeterMatch works, so I just used it.

 

[Adfalenski]

The oil pressure gauge wire comes off of the sender and goes to the firewall connector block. From there it goes to the connector at the back of the instrument cluster. In the instrument cluster it is a plastic flex circuit board to the gauge stud.
if any of these connections are misaligned or loose, the gauge will not work.