Technical Fiat 500 oil pressure plug

[Shanil]

I find that my oil light on speedo meter works even though the wire going to the oil pressure plug on engine is taken off, does anyone know why this is or is the oil light controlled from somewhere else?

:bang:

 

[seicentom]

I don't remember but why don't you have a look at the electrical diagram in the online haynes manual via the link provided by oopsadaisy.(Thanks mate)

http://members.lycos.nl/dm5675/haynes/Haynes_UK.htm

 

[oopsadaisy]

I find that my oil light on speedo meter works even though the wire going to the oil pressure plug on engine is taken off, does anyone know why this is or is the oil light controlled from somewhere else?

Hi Shanil

As far as I know, the oil pressure sensor actually breaks the circuit when it operates (under oil pressure) which makes the warining light go out.

Therefore it would be correct that the light would come on when you pull the wire off.

All this indicates to me that your oil pressure sensor is faulty.

 

[Shanil]

Hi Oppsadaisy, the oil light goes off as well when I raise the accelarator, I will change the oil plug sensor but the light really shouldnt go out when the engine speed increases ssince the oil plug wire is pulled off

Hi Shanil

As far as I know, the oil pressure sensor actually breaks the circuit when it operates (under oil pressure) which makes the warining light go out.

Therefore it would be correct that the light would come on when you pull the wire off.

All this indicates to me that your oil pressure sensor is faulty.

 

[oopsadaisy]

Hi Oppsadaisy, the oil light goes off as well when I raise the accelarator, I will change the oil plug sensor but the light really shouldnt go out when the engine speed increases ssince the oil plug wire is pulled off

Sorry Shanil, do you mean that the indicator light goes off when the engine RPM increases, even though the wire is pulled off the sensor?

 

[Shanil]

Yes even though the wire is pulled off the light goes off at high RPB but comes back on when the engine idles, it is as if the oil plug is actually working even though the wire is pulled out

Should I c heck the wiring?

 

[oopsadaisy]

Should I check the wiring?

Definitely! It sounds like the wiring to battery charge warning light and the oil pressure warning light may have been switched.

With the old dynamo on the original 500 engine, (pre alternator) the charge warning light would come on at idle and go off when the engine RPM increases.

With the wire to the oil pressure sensor disconnected, it should be impossible for the oil pressure warning light to work at all.

Good luck!

 

[Shanil]

Thanks got the wiring checked and seems there was some wiring problem but now I find the oil light comes on during ignition but goes off completely and does not come on when engine idling which used to happen in the past is this normal? when I turn engine off and turn it on again the oil and dynamo lights come on, does the oil light come on only if there is an issue with the oil pressure or should it also come on together with the dynamo light when engine idling?

Restoring the 500 not so easy as I thought next month it will go in for full paint job and new upholstry, plenty of good parts available on ebay italy site

Definitely! It sounds like the wiring to battery charge warning light and the oil pressure warning light may have been switched.

With the old dynamo on the original 500 engine, (pre alternator) the charge warning light would come on at idle and go off when the engine RPM increases.

With the wire to the oil pressure sensor disconnected, it should be impossible for the oil pressure warning light to work at all.

Good luck!

 

[oopsadaisy]

Thanks got the wiring checked and seems there was some wiring problem but now I find the oil light comes on during ignition but goes off completely and does not come on when engine idling which used to happen in the past is this normal?

Yes that is perfectly normal.

In fact if it did come on on idle I would suspect a problem with the oil
pump.

By the way Shanil, I was in Lanka just before Christmas two years ago - it was very odd to see Christmas decorations in the Colombo Hotels and it was 32 degrees outside!

 

[Shanil]

Hi Yes in Sri Lanka they do celebrate Christmas a lot especially with the decor, as you may have seen already Sri Lankans look for any excuse to party

Yes that is perfectly normal.

In fact if it did come on on idle I would suspect a problem with the oil
pump.

By the way Shanil, I was in Lanka just before Christmas two years ago - it was very odd to see Christmas decorations in the Colombo Hotels and it was 32 degrees outside!