O K so here goes. Sorry this has been spoken about more times than the England squad !
1.9 1Y D she starts and out goes the oil warning lamp, good so far THEN the lamp comes on with the BOD after about a minute. Checked oil pressure and very good, changed sensors X 2 and still the same BZZZZZZZ ! Tad confused as during the WIKI and Forum searchers I am mixed up as it is mentioned that it is connected to the alternator (I do not have a rev counter) Is it possible to disconnect the buzzer and still have the warning light working ? Someone disconnected it and fitted a pressure guage and I would go down this route but would prefer it all working as it had done for the last 25years. Ideas and experiences please.
Pete
If you only want the LED function, your best option is to revert back to the earlier oil pressure warning system as originally fitted as this is more reliable than tampering or modding the BoD circuit. In earlier vans (pre BoD), the LED was directly conected to the 0.3bar oil pressure switch and not controlled by the BOD circuit in the speedo. I did post a thread on how to do this, I will see if I can find it.
If you want the BoD system to function correctly then you need to establish what the problem is. A common problem is fitting the incorrect type of oil pessure switch as they are different not only in respect to the 'pressure' rating but also regards wether each switch 'opens' or 'closes' with pressure. The low oil pressure switch 'opens' and the higher oil pressure switch 'closes' with pressure applied. That can be checked quite easily at the switches themselves (with engine running) using a multimeter but also needs to be checked directly at the BoD to eliminate any wiring/connector/pcb problems. The next check is to measure wether you have the Alternator pulse arriving at the BoD and this is normally done with an oscilloscope but you could use a multimeter set AC volts in the range of approx. 0-20V ac. If those checks are Ok and the oil pressure has been verified as being 'good' you can then look at the possibilty of a faulty BoD PCB. However, they are/were very expensive as new items (if still available) and second hand is probably your best option but it must be a Diesel type and not one from a petrol van.
Mine was a case of crusty wires to the senders. They were routed over the hot engine / exhaust and were shorting out when the engine was hot i.e. when running.
Thanks for the comments. Had a good look today and the Tape/Ribbon is not looking too good, a tad fragile in fact. Going to revert back to just having a oil pressure warning LED and thinking of fitting a new connector block and doing away with the ribbon which has done well but now needs to retire and rewiring with real cable and spade connectors.
The BOD pcb is quite impressive for its age though but I love my van because it is simple and I can do without the electronical stuff.............keep it simple and keep it reliable methinks.
