Golf 3 Dsl tacho/oil light/speedo fail

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Thu 17 Nov 2005 09:14
Golf 3 Dsl tacho/oil light/speedo fail - oilydavid
I have an intermittent..now semi-permanent failure of the tacho,speedo and a flashing oil light. I have cleaned the earth on the end of the engine block adjacent to the main harness junction, which I have unplugged to check connections. Also removed instrumnet pack and joggled multipin connector to back of pack...
Can anyone advise...I suspect either earthing fault or dry joint on printed circuit board where female multi pin connector is mounted.
David Adams
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Thu 17 Nov 2005 11:43
Golf 3 Dsl tacho/oil light/speedo fail - Screwloose
David

There's rather a lot of different diesels/control systems on the Mk III Golf. Can you look out your engine code [on the cam-belt cover label/service book/build label in the boot floor/rear sill/wheelwell area]; it'll be anything from 1Y to AFN.

While you're doing that; check that the rubber waterproofing boot on the driver's door courtesy light switch is still there.
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Thu 17 Nov 2005 12:26
Golf 3 Dsl tacho/oil light/speedo fail - oilydavid
Engine is a 1Y.... will check the courtesy light rubber tonight.
Thanks
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Fri 18 Nov 2005 08:41
Golf 3 Dsl tacho/oil light/speedo fail - oilydavid
Tried another instrument pack..problem still exists....courtesy light rubber seals seem OK...trying to trace earth wire from pack back through fuse box to earth in engine harness.
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Fri 18 Nov 2005 11:52
Golf 3 Dsl tacho/oil light/speedo fail - Screwloose
David

The 1Y uses that little black 18-pin Siemens pump-control ECU on top of the fusebox to relay engine speed info from the pump to the display unit. With no speed reading the higher pressure oil light switch monitoring circuit trips the flashing oil light [circuit fault] signal.

The ECU's sensor for the driver's door [ECU pin 7] can get full of water and corrode; disabling the speed info. Try disconnecting the [3-wire?] courtesy light switch and see.

Good luck; these 1Y's are not nice to fault-find obscure faults on.
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Fri 18 Nov 2005 15:09
Golf 3 Dsl tacho/oil light/speedo fail - oilydavid
Thank you for your note...Imust apolgise ..its an AAZ engine, (my other daughters car is the 1Y) does this make any difference
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Fri 18 Nov 2005 15:11
Golf 3 Dsl tacho/oil light/speedo fail - oilydavid
The car is also LHD but I presume that will not affect your comments.
Thanks
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Fri 18 Nov 2005 20:34
Golf 3 Dsl tacho/oil light/speedo fail - oilydavid
I have fixed the car!!! Thanks very much. The clue was lack of speed signal causing more than tacho failure...the connection to the rear of the alternator was dirty...waggled it and everything worked... will now clean it carefully.... your forum is fantastic.
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