Oil Pressure Sender electrics?

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hellfirechrome

hellfirechrome

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I have an electric oil pressure sensor plugged into in my SBM. How does it work? As in; does it give a voltage across the range of 0-12v (or whatever voltage provided by ground) as the oil pressure builds up? I want to adapt this to an older electric gauge and am curious what to expect....
 
I bet it varies the ground with pressure. if you run the wire straight to ground it should show you pegged pressure. High pressure . little resistance, low pressure. more resistance
 
pishta said:
I bet it varies the ground with pressure. if you run the wire straight to ground it should show you pegged pressure. High pressure . little resistance, low pressure. more resistance
Click to expand...

Yep.
 
The Mopar sensors like this are designed to work off of lower voltage than the 12 system; it comes from a pulsed regulator in the dash, that passes through the gauge and the through the sensor in a series circuit to ground. That pulsed regulator gives an RMS DC voltage of around 5 volts to the gauge + sensor.

The sensor varies its resistance with pressure: low pressure is around 70-ish ohms and high pressure is around 10 ohms. So, if you use it with another gauge, you need to expect that resistance range. Other gauge systems use a much higher resistance range, with much lower sensor and gauge currents, so you need to do some serious adapting to make this work at all.
 
I'd like to use it with the assembly from a '51 Plymouth Fuel gauge. Might actually be similar resistance..... dunno, will play and see. Worst case, it doesn't work! Maybe I'll hire a nerd to build a reducer/signal unit from an Arduino computer or somehting high tech :)
 
Actually, that may indeed be close! The gauge system really comes from the older 6 volt systems and that may be what your '51 had. That is the reason for the regulator... to drop the voltage to the gauge/sensor system to simulate a 6 volt system.

Here is a link to very similar VW thermal gauges to see how these work; the regulator described works identically to the Mopar regulator.
Electric Fuel Gauges
 
That's fantastic news! I'm simply gonna run the sensor to my fuel gauge (on a runtz reducer since I went 12 volt) as a test, and I should have my answer :)

The car originally had a pressure line from the block to the dash oil sensor; my goal is to use the oil temp gauge's faceplate on a fuel gauge (same year, will fit!) so I don't have to run a high pressure oil line into my cabin! Always hated that
 
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