Oil pressure gauge conversion from ‘idiot guage’ E350

[Bikersmurf]

Every once in a while my ‘97 oil gauge reads low. If I fiddle with the connection an the sender (switch) it’ll go back to reading ‘normal’. I know it doesn’t measure pressure... other than it being more than 7 psi. If it wasn’t also that the oil pressure light also shines, I could more easily ignore it.

I figure the sender needs to be replaced... but do I put in a pressure switch or or a STANDARD PS60 actual sender. With the sender the resistor bypassed it’ll give a pressure reading. Has anyone done this?

Or should I just replace the ‘switch’ and save the hassle?

 

[WOODY2]

T and use both?

 

[Bikersmurf]

T and use both?

It’s the same gauge. When a minimum pressure is reached, the sender closes & Ford added a resistor so that the gauge would move to 3/4 of the way up. The gauge always indicates the same pressure regardless of what is actually happening.

I could add a second gauge, but what I’m proposing is removing the resistor and replacing the switch with a sender that gives varying output so the needle actually shows a pressure reading... and thus if something is off from normal.

The idiot light should still work if resistance is too high (as it currently does) and the gauge will read lower once it warms up and at idle... and higher with higher revs. If it goes outside of the normal range it should give the operator a clue why the injectors stop firing and it won’t run.

 

[Mwilliamshs]

I would bypass the resistor (just solder in a 18 awg wire) and use the sender. I've done it and it works. You can use a temporary mechanical oil pressure gauge to develop a known "scale" for your stock guage. In my 4.0 Ranger with the above mods, N was 20, O was 25, R was 30, M 35, A 40, L 45 and the last bar was 60 psi. I ran 50w for just a bit to get the highest reading just for informational purposes but I was in high school and thought it was clever. I'd avoid that practice now.

 

[Bikersmurf]

I would bypass the resistor (just solder in a 18 awg wire) and use the sender. I've done it and it works. You can use a temporary mechanical oil pressure gauge to develop a known "scale" for your stock guage. In my 4.0 Ranger with the above mods, N was 20, O was 25, R was 30, M 35, A 40, L 45 and the last bar was 60 psi. I ran 50w for just a bit to get the highest reading just for informational purposes but I was in high school and thought it was clever. I'd avoid that practice now.

Good to know.

Do you happen to know if there is a sender with 1/8th npt? The PS60 sender I’ve found had 1/4npt. I believe the 12/‘96 sender is 1/8th. I won’t know for sure till I pull the old one. I’ll buy a fitting to adapt if needed, but my first choice would be to find one that is the smaller fitting.

 

[Mwilliamshs]

No, I am not aware of the threads of even the fittings and sender I have used, much less those I have not. I found the sender by reading of the modification in a forum specific to the vehicle (Ford Ranger) rather than its purpose (basic transportation). I suggest you attempt the same (7.3 PSD forum rather than camper van forum). The broader the appeal of the post or question, the less likely it is to be significant or satisfactorily answered here versus a bigger, broader forum like Ford Truck Enthusiasts or OilBurners.

 

[Bikersmurf]

No, I am not aware of the threads of even the fittings and sender I have used, much less those I have not. I found the sender by reading of the modification in a forum specific to the vehicle (Ford Ranger) rather than its purpose (basic transportation). I suggest you attempt the same (7.3 PSD forum rather than camper van forum). The broader the appeal of the post or question, the less likely it is to be significant or satisfactorily answered here versus a bigger, broader forum like Ford Truck Enthusiasts or OilBurners.

So far what I’ve found in those forums was PS60. Which seems to be a direct fit till 7-15-1996 +/-. I’ll dig a bit more, but so far an adapter is looking like it’ll be in my future.

 

[Bikersmurf]

The original sender.
Borg Warner equivalent to Standard PS60

Installed with elbow and adapter fitting so wire will reach.
Reading at Hot idle.
Reading at 2k RPM

Where it Reads Cold.

I’ve not removed/bypassed the resistor from the instrument cluster.

After fitting the new sender that has variable output rather than a switch, the output on the gauge looks the same. nothing exciting to see.

Could the 7.3 oil pressure possibly be that consistent at the low pressure reservoir? Is there a regulator or pressure relief that fixes the oil pressure? Is the electrical gauge so inaccurate that it doesn’t fluctuate?

Short of pulling the sender and hooking it to a compressor, thoughts to figure it out? Should I just leave well enough alone and look for an actual problem to fix?

 

[DaveInDenver]

So all you did was remove the series resistor in the circuit and ran a transducer to the existing switched gauge? You might need to put a resistor in parallel with the new pressure sender to show any movement but with it the readings won't necessarily be linear.

FWIW, there's a couple of companies that make black boxes to let you match senders and gauges.

TechnoVersions - MeterMatch for Analog Gauge Correction

Accutach Company

Electronic Automotive Products Instrumentation Service Tachometer Calibrator Tool And helpful information

accutach.com

 

[Bikersmurf]

So all you did was remove the series resistor in the circuit and ran a transducer to the existing switched gauge? You might need to put a resistor in parallel with the new pressure sender to show any movement but with it the readings won't necessarily be linear.

FWIW, there's a couple of companies that make black boxes to let you match senders and gauges.

TechnoVersions - MeterMatch for Analog Gauge Correction

The

Accutach Company

Electronic Automotive Products Instrumentation Service Tachometer Calibrator Tool And helpful information

accutach.com

I've not removed any resistor. All I've done so far is to replace the '97 sender with an '87 sender (with a couple fittings to plumb it in). The '87 sender is the same as a Standard PS60 which should make the gauge work. The PS60 was used for a wide range of OEM gauges... even a '77. I'm leaning towards leaving well enough alone, and doing nothing.

 

[Bikersmurf]

Oil Pressure Switch to Sender Conversion - Ford Truck Enthusiasts Forums

1987 - 1996 F150 & Larger F-Series Trucks - Oil Pressure Switch to Sender Conversion - 1996 F350 5.8L my oil pressure gauge died on me. the switch went bad. instead of replacing it, I decided it was time to convert the gauge to an actual working gauge and instead of replacing the switch with a...

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