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1989, circuit board replacement
Posted: 23 Oct 2009, 19:22
by dario
I've had a problem with the oil buzzer going off at random. Changed sensor and other stuff but it doesn't work. The only thing left, which is the first thing my mechanic wanted to do(!), is to change the circuit board. Unfortunately VW has stopped making these. Can a new one be made from scratch or do you know anyone who has a good one?
Re: 1989, circuit board replacement
Posted: 23 Oct 2009, 19:31
by camper
I have a spare one got one off ebay & never used it.Run a diesel but converting over to visual oil pressure gauge.Not sure though if petrol or diesel curcuit are the same as it could be ether& its never been tested by my self .Pm me if you are interested.
Re: 1989, circuit board replacement
Posted: 23 Oct 2009, 20:23
by AngeloEvs
Only available used and, more often than no, you need to buy the whole dash. As long as the dash panels have the same layout you can use a post 86 Diesel dash membrane PCB. I would verify that the membrane is causing the problem first. There are other causes for the symptoms you describe,e.g, not receiving a rpm pulse from the coil, faulty oil pressure switches/connection and last but not not least the DOPS (buzzer of doom) pcb in the speedo. As a temporary measure you can convert back to the earlier 'non buzzer of doom' oil pressure warning system and remove the DOPS board altogether. If you want details let me know. You can always revert back when you eventually find a replacement membrane panel.
Re: 1989, circuit board replacement
Posted: 23 Oct 2009, 20:34
by billy739
petrol and diesel are different
no difference on age tho
only fitted from late 86
i should have a good used one hear somewhere.
Re: 1989, circuit board replacement
Posted: 23 Oct 2009, 20:42
by AngeloEvs
You can use a diesel membrane in a petrol........only difference is the glow plug LED, remove it, Petrol ignores pin 15 on the dash MC.
Why do you say they cant be used?
Re: 1989, circuit board replacement
Posted: 24 Oct 2009, 10:46
by billy739
are we talking membrane or buzzer circuit?
i am talking buzzer circuit , i know the diesel membranes are ok for petrols.
Re: 1989, circuit board replacement
Posted: 24 Oct 2009, 11:08
by CovKid
Other alternative is to 'hardwire' the dash. Few of us have done that.
Re: 1989, circuit board replacement
Posted: 24 Oct 2009, 11:35
by AngeloEvs
The DOPs PCB's are different but still listed as available from Germany (at ridiculous price of £60-00 + ). If your mechanic is referring to the DOP pcb and not the membrane pcb then It's a lot of dosh to fork out without being absolutely certain that it is faulty. Its an overly complicated system that is flawed and unreliable and there are better and simpler ways of monitoring the condition of the two oil pressure switches.
Re: 1989, circuit board replacement
Posted: 24 Oct 2009, 11:50
by rattybird
i had the same problem with the pcb board broken its a all 2 common thing to happen ! so i just changed the dashpod for the sake of a few squid !

Re: 1989, circuit board replacement
Posted: 25 Nov 2009, 20:41
by dario
It seems to kick in as soon as I hit 2000 rpm. Could this be a clue?
Re: 1989, circuit board replacement
Posted: 25 Nov 2009, 21:26
by billy739
the buzzer is designed to work only if oil pressure is low below 2000rpm
Re: 1989, circuit board replacement
Posted: 26 Nov 2009, 00:10
by AngeloEvs
Might be that your DOPS circuit is not getting the earth connection via the high oil pressure switch. Get your mech to check that the high oil pressure switch (close to the water pump) is closing (connecting to chassis). On a healthy engine started from cold this will normally connect to earth even when idling. alternatively connect the feed wire to this switch to chassis and see if the fault continues. My understanding is that the buzzer and LED will kick in if oil pressure is lower than it should be above 2000rpm. Will check that tho!
Re: 1989, circuit board replacement
Posted: 26 Nov 2009, 15:36
by drliamski
I am after a replacment pcb mebrane, looking for a 89 diesel with rev counter. If anyine has one please pm or email me,
glenmurdoch@gmail.com. Not that keen to undertake a hardwire just yet!
Cheers
L
Re: 1989, circuit board replacement
Posted: 26 Nov 2009, 18:49
by R0B
try using the wanted forum
I am after a replacment pcb mebrane, looking for a 89 diesel with rev counter
Re: 1989, circuit board replacement
Posted: 27 Nov 2009, 07:26
by drliamski
R0B wrote:try using the wanted forum
I am after a replacment pcb mebrane, looking for a 89 diesel with rev counter
Will do mate.