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grnoval

New Member
So, i've successfully changed the clutch - on the test drive, got about 5 miles in, and the oil pressure light came on. borrocks.

Pulled over, checked everything, had oil, nothing blindingly obvious, so got home.

Started by changing the oil pressure sensor - no change. Then noticed i'd got the wire caught between the firewall and the back of the engine somewhere, gave it a tug and.... oh two wires.

Replaced the wire, and oil pressure light went off - but wasn't on when on ignition either - double borrocks.

So to check my sanity, thinking if sensor is disconnect pressure light will be on.... and no light still.

Its a 2000 TD5, no idea if the oil pump bolt has been done.

Any ideas? Should the circuit failsafe (ie show warning light if sensor disconnected? what else could it be?

I'm hoping not oil pump, as I had the sump off when doing the clutch (previous attempter had cracked the sump - FFS what is it with people?) so praying i haven't buggered the pump whilst getting the sump back on.

CHeers

Si
 
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the oil pressure warning is different like other circuits, it's a simple NORMALLY CLOSED pressure switch hardwired to the instrument pack which is connected to earth and goes off when the pressure opens the contact...so disconnecting it will let the warning LED without earth... it has two wires but the black one is useless, it's earthed via body, if you touch the white/brown wire to earth it must come on... unless the wire is interrupted

the green wire is live from fusebox
 

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Thanks for that Sierrafery - so my second initial diagnosis (yeah I know) of a trapped wire (ie it going to earth) would be correct for the light being on permanently.

But what of the current situation where the light won't come on at all - not even at ignition on - any ideas?
 
Evening James - yep I know that now ;);););)

Just trying to get to the bottom of why the light won't come on at all now - although I will admit to being slightly more hopeful that it isn't a buggered oil pump...

I ran a new wire in from the point by the the inlet manfold right the way across to the sensor, so hopefully that has alleviated the buggered wire issue - but I don't understand why no light at all at the moment.
 
the flickering might have been caused by the chaffed wire which touched the body ....did you touch the white/brown trace wire to earth/body with ignition on and no warning? ..it means that the wire to instrument pack is interrupted , if you get light with wire to earth but nothing with it plugged it means the switch doesnt work, you can connect the black wire to a close earth point just to make sure but the switch is earthed through it's fixing anyway... see again my first post and concentrate then IMO you'll understand
 
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@james - there might be two wires, but only the white one has a connector on the sensor end.

@sierraferry - no flickering of the light - I was driving, it was on. Now changed sensor, light still on. Repaired wire, light off permanently. Hence the tried disconnecting sensor in the thought that it would cause light to come back on - light off permanently. Could you check the wording of your first reply as it doesn't quite make sense thanks muchly
 
maybe my english has some lacks but i can't find anything wrong in my first post:eek: ... just tell me that: do the light come on if you touch the white wire to body with ignition on?...if not the wire is interrupted somewhere.... if the light comes on by touching earth with the white wire(ignition on pos II) but doesnt come on connected to the switch then the switch is fubar'd simple as that

i'll try to reformulate but the gist is the same...the lamp gets ignition live from the instrument pack, the switch is closed to earth when no oil pressure is present = light on, when the pressure rises the switch opens = light off. I can't put it other way sorry
 
Thanks Sierraferry - more likely my misunderstanding :) so contact to earth light on, switch open light off, so my pulling the cable wouldn't induce light on, it would induce light off. Not exactly a failsafe is it :)

Right, off to check the wires then
 
hahahahahah Mucho thanks Sierraferry - my spliced in bit of wire wire was fubar too!! when I tested it, there was a pip and then nothing (rather than the continuous bell of a good circuit). a bit of chopping and changing and I have oil pressure and a light that comes on with ignition, and goes off with pressure - result :)
 
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