sounds like the right part.
the description is right.
I'd put it in and run it ...and take my time getting a proper one from a
vanagon-savvy vendor to install at your leisure.

I needed an oil pressure switch for a diesel vanagon engine on a trip once.
I figured a discount parts store might not list that part, and I was
prepared to ask them for one for a VW bug , since I know that would fit.
 It was  a California discount parts store chain ...Pep Boys, or something
like that.
no need to worry ..
their parts book said 'VW oil pressure switch, 1950 to 1990 ..'all'  )  lol.
it worked.
and that was the opposite failure , I was driving down the road ..
oil light came on...but I new it wasn't a real indication of no oil
pressure.

----- Original Message -----
From: "Rocket J Squirrel" <camping.elliott@GMAIL.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Sunday, May 29, 2011 10:28 AM
Subject: Re: Yeppers -- failed oil pressure switch alright.

> My FLAPS have a replacement oil pressure switch. It is a BWD S4026.
> Website says compatible with: "Vanagon Campmobile, H4 - 1.9L vin B
> 1915cc type DH - MFI GAS OHV"
>
> I can't find any more information about this part.
>
> There appears to be a mention of this switch, according to Google, at
> <http://www.vanagon.com/info/articles/oil-pressure-probs/index.htm> but
> vanagon.com is taking ages to load. Down?
>
> I'm going to assume it fits. The threads look the same. If it doesn't
> work I'm no worse off than I am now unless it needs more than 0.3 bar to
> shut off the oil pressure lamp, then I'll be confused.
>
> On Sun, 2011-05-29 at 12:18 -0400, David Beierl wrote:
>> At 12:01 PM 5/29/2011, Rocket J Squirrel wrote:
>> >(1981.9L) Got the tin off the bottom of the left head. Three 13mm and
>> >one 12mm? Who designs such things?
>>
>> Sounds like someone put a Japanese bolt in there.  J.I.S. bolts have
>> a 12mm head where M-series have 13.
>
> I believe it was the forward inner tin-holding fastener. Goes on the
> exhast manifold flange. It's a skirted nut that takes a 12mm wrench. Not
> much clearance there, I don't know if a 13mm head would fit.
>
> The other fasteners are 13mm-headed bolts. Oh well.
>
>>
>>
>> >The switch reads open to frame with the engine off, so it's a goner.
>> >Found the fossilized remains of what appears to be an ancient
>> >Pre-Columbian rubber boot on the switch. After than crumbled off, the
>> >the brass push-on connectors had nice green verdigris.
>>
>> Because of the sliding action the terminal is self-cleaning to a
>> considerable degree.  This is a signal connection so contact
>> resistance may not be so critical.
>
> Well, here is my simple 9-step troubleshooting process.
>
> 1. Locate the wire that goes to the switch. 2. Read resistance to frame
> with engine off (read open). 3. Short wire to frame. 4. Observe dash oil
> pressure lamp comes on. 5. Re-connect and confirm that switch does not
> turn on lamp with no oil pressure. 5. Sigh. 6. Clamber underneath and
> remove tin. 7. Inspect switch, looks ancient. 8. Re-check continuity
> from tab on switch to frame. Still reads open. 9. Press really hard to
> make sure I'm cutting through corrosion and build-up on tab. Same
> result.
>
> I think this is pretty conclusive.
>
> -- RJS