Jay,
I would appreciate if you could tell me more as where to check the voltage
for the OS.
Didn't find any simple explanation in the Bentley.
Do you mean checking the voltage from the van, or checking in parallel when
van is running with the OS plug?

More info please in good and simple English (I'm French)

Regards, Ben

What I mean is an unplug OS as no voltage, so it need to be plug! If it's
plug and you check in parallel, you will get the van voltage??? Also, on
the 3 wire OS, the 2 white one are for heating, the green one is for the
sensor by it self. Where to put the 2 Meter wire?
Between chassis and connector?

Check my site at the following link and tell me a combination of letter to
do this check
http://pages.infinit.net/engine/os_sensor.htm

Regards, Ben