Convert Oil Pressure gauge back into a real gauge? Possible?

X300
1

So, the way I understand it, Jaguar was getting too many customer complaints about low oil pressure readings at idle in the mid-90’s, so their answer was to add an oil pressure “switch” in place of the “sending unit/transducer”. By adding a switch (and a resistor in the line, of some specified value), the gauge would just rise to about midway to indicate pressure, but giving no details or fluctuation to indicate high or low pressure.

I am hoping that someone has been able to successfully retrofit a transducer (either C46272 or possibly DAC7879), remove the resistor, and get their oil pressure gauge reading as originally intended again?

If so, which transducer worked? What was involved? Is it more complicated than just resistor removal and sending unit swap?

Any ideas or thoughts appreciated.

2

If you have an early car the sensor may still be fitted?

See if it’s a large unit with 2 terminals

3

Mine definitely has the switch (a 1996). I just removed the switch, as it was leaking badly, and I am considering putting in a sending unit to see what happens, but the sending units aren’t cheap… wish I had one laying around to test it.

4

Yeah they are expensive to manufacture

On vauxhalls if the gauge wire is disconnected it goes the maximum pressure. (Off scale)
And if you put the wire to ground it goes to zero.

So you can connect the gauge wire to the pressure switch for a brief test.
Start engine and should goto maximum.

5

I have done this modification when I worked at the Jaguar dealer. Here is the TSB we got and I don’t know if the gauge will read correctly with a transducer instead of the switch. (I never tried it the other way around)

There is no procedure to ‘reverse’ the configuration in the PDU/WDS/IDS menu.

good luck.

15-13 Oil Pressure Gauge – Fluctuation.pdf (33.8 KB)

bob

6

Bob,
Jim Butterworth played with this way back and did this write up:

http://jimbutterworth.co.uk/8instruments.htm

Others have fitted analogue guages IIRC over the years.

1 Like
7

Many thanks, this article answered all my questions… bottom line, just not worth it unless I owned an early 1995, which I don’t. I went ahead and got another switch. Don’t really want to mess around that much with the instrument pack circuit.

Much appreciated!