Oil light not coming on

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sandyman
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Oil light not coming on

Post by sandyman »

Until very recently the oil light was functioning correctly- coming on when ignition was turned on and then switching off during driving. The last couple of times it has not come on at all, but van drives well. It has recently has a head gasket change, but it was fine up till then and also for 2 months since. The van is 1986 and has a Golf 1.9 TD engine.
I've read quite a few posts about general woes concerning the oil light though it seems most are about it staying on or the problems are a result of taking off the dashboard whilst trying to fix other things!
What should I check first?

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Mocki
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Re: Oil light not coming on

Post by Mocki »

First check I would do is visually inspect the wiring at the oil pressure switch ( Es) and then bridging the pressure senders out to see if the loom is at fault or the senders
Steve
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sandyman
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Re: Oil light not coming on

Post by sandyman »

Thanks Mocki can you tell me where it is exactly? How do you bridge the pressure sensors exactly? Excuse my ignorance but new to all this and trying to learn!

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Mocki
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Re: Oil light not coming on

Post by Mocki »

I.cAnt tell you , sorry, I know nothing of those heavy oil burners , but to bridge out the sender , if it’s a two pin plug, unplug it and join the two pins on the plug together with a link wire , if it’s a single pin connection, Earth it to the engine block
Steve
tel / txt O7947-137911
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1988 2.1 Caravelle TS TinTop Camper 
 

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Aidan
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Re: Oil light not coming on

Post by Aidan »

The low pressure switch is the one that initiates the warning light, that is closed no pressure and opens at 3psi when you start the engine, so the dash is looking for continuity on the low pressure circuit when you turn the ignition on and the light will come on and then go out when the circuit goes open so either your low pressure switch has failed open (unlikely) or there's a wiring fault such as the wire has come off the sender or has become disconnected at the dash

The fact that the buzzer of doom isn't coming on when you rev past 200rpm probably means you have decent oil pressure but it could be the b.o.d circuit has failed (you can test this by disconnecting the wire to high pressure sender and revving engine past 2000rpm - buzzer should sound)

you need to find the low pressure switch (front of head on diesel I believe) and check if it is connected, if it is then try removing the connector and cleaning it and the terminal on the switch and remake connection and see if light works normally, if it doesn't then remove the terminal and earth it to the body/engine and test to see if it works now, if it does the wiring is ok and switch has failed if it doesn't then you'll have to check the connection at the dash and in between if necessary

I expect wire has come off/broken or has become contaminated with oil or corrosion

sandyman
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Re: Oil light not coming on

Post by sandyman »

Cheers Aidan will check all this out when I get a minute! Do you think I'm ok driving it around with this problem?

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