I would begin with the multi-wire connector on the instrument cluster. Bad connections there can cause all sorts of grief. For the oil pressure warning buzzer there are two pressure sensors. The .9 bar sensor is the one that activates the buzzer and lamp over 2,000 rpm. It is a fail-safe. In other words the switch is normally open (off) and closes when pressure is sufficient. As such any bad connection will make this give a false indication. There is a connector for the two switches in the engine compartment. The contacts corrode and the wires break inside the insulation. 

Dennis

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of Marc Perdue
Sent: Friday, May 1, 2015 3:14 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Electrical weirdness

Hi all,

I took my '87 Westy in for inspection yesterday. I've been working on getting it back together, slowly, after getting it painted. When I got to the shop, about 3 miles from my house, the oil pressure light and alarm turned on. They were going to reject the van because the high beam light wasn't working. I had them change the oil and filter, because it hadn't been done since all that dirty bodywork was done and the oil light was no longer on. They took it for a test drive and the alarm came back on, but the high beam light was then working, so it passed inspection. They checked the oil pressure, which was fine, so they're replacing the oil pressure sending unit.

I can't help but think that there might be an electrical issue somewhere and that the problem is not actually the sending unit, but I haven't heard back from them yet today. Do you all have any thoughts on a connection between the high beam light failure, then non-failure, and the oil pressure light/alarm?

Nervous in Va...
Marc Perdue