Oil Pressure Gauge & Light

[Barra]

Hi Guys,

well tearing out what hair is left with this OP gauge + light.
Sender has continuity when slightly pressurised by air with the multimeter checking it, gauge was OH by Lionel Otto Instruments, Circuit has continuity, oil pressure is good using a test set plumbed in, light comes on when connected to what should be the feed connection but does not go out when the engine is started.
The biggest difference between the new sender and the old is that the old had 2 terminals but both appear to be common, whereas the new sender has only 1 terminal. Why did the old one have 2 terminals??? when the VinWire harness has only one connector.

By my reckoning - it is all in line with the Aust ARMY wiring diagram but nothing is working. HELP!!!

[glbest]

Lionel Otto was an ex-army apprentice instrument maker, and most of workers were ex-army tradesman in 1990. so it was done correctly they had contract in bne for over twenty years

[Chazza]

Not sure Barra; however; the circuit must be broken for the light to go out i.e. when the switch opens.

Investigate the circuit with the switch held open. Is it possible to use a probe to hold the switch open while you test?

Cheers Charlie

[mike_k]

Barra,

Have you replaced the sender with the same one?

 If you are using the original Smiths gauge, you need the correct sender with the 2 male terminals. This is a 0 to 100 psi unit and still available. 

 It sounds like you might be trying to use a pressure switch, which is either on or off and normally connects to the oil pressure light in the speedo which was not used in the military 2As.

 Maybe try your original sender if it still works…

 Here’s a photo of the type for the Smiths gauge, hopefully this helps.

[Barra]

Hi Mike,

yeah I bought a new type with only 1 spade connector so will test the old one tomorrow arvo. It does have the 2 spade connectors, I think the old one still works, used low pressure air to open the cct with multi on a continuity check so appears to work ok.

Cheers,

Barra

[mike_k]

 
 It’s worth trying the old one Barra,

 Hopefully it still works, but they are still available.

If your new one looks like this, it’s a switch for the light in the speedo, not a pressure transmitter for the gauge.