Buzzer of Doom is back...feck

[pocolow]

After many months of quiet motoring the bliddy BOD is back. Did an oil and filter change two weeks ago(quantum 15/40) and genuine VW filter all fine then yesterday...flashing oil light and BOD..feck feck. It can come on within seconds of driving away, then go off,then on, with no discernible pattern. Both pressure switches were changed 10 months ago (Brickwerks ones). Tonight I took off the Dash multi pin connector...well it fell off (broken plastic) cleaned it up and then taped it back together ...But still no joy... The BOD and oil light only come on when driving ,no amount of revving whilst stationary will set them off ....Any other suggestions guys and Gals..ps its a 1.6td 1990 around 90,000 miles.

[quagmire]

Oh no,sorry to hear that Mark

[margaret]

So how long have youhad your buzzer of doom for then? did you actually manage to drive through it? you are bracer than I ; being a catastrophiser I immediately thought the worst but it seems to be located on the dash ..... would a new dash pod help? MARGARET

[pocolow]

Hi Margaret, If the problem is in the dash pod(broken circuits) as opposed to bad earths or connections, then a new dash pod would help. But and its a big but...you can't get new ones only second hand. So there is no 100% guarantee you'll fix the problem.

[margaret]

Hi fellow northerner...High Legh ....although Ive gone south a long time now... comforting words - sounds like I might be driving with the BOD for a while... Im still hopeful though Can you get that blue plastic circuit bit new someone told me you could but I havent tried Vw as yet..Maraget

[Plasticman]

Hi mark, mine did/does the same, changed the senders, checked with a wet guage, all ok so earthed the switch , silence will fix at a later date or disconnect the buzzer and leave a light
mike

[jed the spread]

make sure you clean the connections on the earthing crowns. Its the on the same one that does your headlights so if you have been having some odd on an off problems with them it could be that. It was on my van.

jed

[CovKid]

I still think that buzzer is a ridiculous addition. If your engine is well-maintained, you're better off without it. If I didn't have enough to worry about. Even my local VW garage sneers at it. By far the biggest hassle with it is it going off when it shouldn't and not so far known anyone who has had it go off for legitimate reasons. Buzzer of doom = stroke victim

[AngeloEvs]

I still think that buzzer is a ridiculous addition. If your engine is well-maintained, you're better off without it. If I didn't have enough to worry about. Even my local VW garage sneers at it. By far the biggest hassle with it is it going off when it shouldn't and not so far known anyone who has had it go off for legitimate reasons. Buzzer of doom = stroke victim

even an aging DG engine regularly maintained will kick the high oil pressure bar switch in at 1000 rpm even after a long run. During the winter that switch kicks in at idle and never drops out..........I agree Covkid, I monitor the state of the high pressure oil switch and ditched the BOD. Most frequently, it only tells you there is a problem with the circuit/wiring and 'sweet FA' about your oil pressure!

[CovKid]

Yup - I'm not alone in that one then.

[pocolow]

UPDATE....After taking the Dash Pod out and using the a second had dash pod in better nick I built one decent one out of the two, cleaned all the terminals and put it back together.......start engine rev....bbbbbbbbbbbuuuzzzzzzzzzzzzzzzzzzzzzzzzzzzz. feck..Take off both oil pressure switch connections and put on new spade connectors.....bbbuuuuuzzzzzzzzzz.... ....Since the buzzer seems to come on at higher revs I recheck the high revs /low pressure switch( This was replaced 8 months ago with one from Brickwerks) The switch was a grey one which on Simon's advice replaced a black one which was causing problems last year and it has been fine for 8 months..I only had A new black switch available(as originally fitted) so I tried that....Bingo...buzzer has gone and so far no problem all week...What I can't fathom is why the grey switch went faulty so quickly and why a black switch, which in theory should be more likely to trip the buzzer works fine But hey it works ..

[jake1953]

Jumping onto this thread, how do I disconnect the buzzer but leave the dash oil light working?

[AngeloEvs]

you have to remove the multipin connector on the rear of the speedometer and this disconnects the BOD circuit.
In order to have the oil pressure LED function directly off the low oil pressure switch (as in pre 86 vans) you will need to do either of the following using the picture below as a reference.

1. replace the oil pressure led with a 12v type (Available as a RED flashing type or standard red) and place a wire link in the vacant connector in the postion occupied by the resistor as shown below.

2. Keep the existing non flashing Red LEd and insert a resistor of any value between 470 (min) and 1500 (max) ohms as shown below.

VW fitted the later membrane with the horizontal connector in early 1985 and all of these were capable of supporting the BOD pcb in the speedo. However, the BOD PCB was not installed on all models and a resistor is crimped onto the membrane instead (early production models). All '85 and onwards dash membranes have provision for this resistor to be placed on the mebrane in order for the oil pressure LED to function without the need for a BOD. Some early dashboards appear to have a BOD fitted but in fact they do not and the oil pressure LED works as in earlier models and controlled directly by the oil pressure switch via a resistor. The space and pads are available for this resistor on all later membranes but the resistor has to be crimped onto the vacant pads and requires specialist tools.

[jake1953]

Thanks Angelo. In your photo, Is that part with the resistor the same as the part that the bod pcb fits into?
If so is it just a case of removing the pcb and fitting the resistor?
Jake

[AngeloEvs]

Yes, thats the connector for the BOD PCB but you don't need to remove the DOPs PCB unless you wish to (simple to remove as the pcb is just held by clips in the speedo housing so worth removing IMO). Just pull the connector carefully from the rear of the speedo. The connector and membrane are also secured by small plastic securing nipples and you just carefully ease the membrane over them and unplug the socket. Fit the resitor (or link if using a 12V flashing red led) and secure the membrane to the rear with a small strip of duck tape.

PM your address and I can send you a 470 ohm resistor (or a 12V flashing Red led) if it helps.....