Electrical issue since 1.9 install

caveman · Post by **caveman** » Mon Mar 16, 2009 7:13 pm

Since i replaced the 1.7 na with a 1.9 na with a serpentine belt system in my Vanagon there is and oil buzzer problem. Once the motor is warm as the rpms come down to about 2300-2500 rpms the buzzer and light come on. If i blip the throttle they go off. At idle or low rpms it will never come on. I really don't think it's low pressure because the lifters never make noise and i have zero oil consumption. I replaced the switches but made no difference. I have forgotten the diagnostic for those switches and am now afraid that the buzzer is doing exactly what's it's supposed to. I had the issue with the tach showing the wrong speed and did the adjustment and was thinking it had something to do with that.

rsxsr · Post by **rsxsr** » Wed Mar 25, 2009 3:42 pm

I need a little more information to be of help. The condition your are describing is the dynamic oil pressure warning system. I would not want to assume you have oil pressure. An external gauge will verify. The system uses engine rpm and oil pressure to activate the warning. There is a 1.6 bar oil pressure switch that came on TD diesels that increases the threshold of the warning system. If you can determine which oil pressure switch is the dynamic one, you can pull the wire off and ground it. This should keep the system quiet. If not, you have an electrical problem to sort. I disabled the dynamic system on my vanagon conversion. What are you using for an rpm signal? What tach? The early diesels got their rpm signal for the W terminal on the Alternator. You mentioned a serpentine belt system. What alternator are you using? Regards.

caveman · Post by **caveman** » Wed Mar 25, 2009 4:01 pm

Thanks for the reply. I have sorted it out. It wasn't oil pressure. I have the original dash with tach and the truck started as a diesel. The new alternator has the w wire. The issue seems to be because the alternator with the serpentine belt system turns much faster than the old one so it confuses the oil buzzer controller. After checking a number of things i just shorted out the switch on the oil filter flange and problem is gone.