I have a customers 86 Westy that has an instrument cluster from a later
model installed.  I have been trying to troubleshoot the battery light
staying on and I am bumping my head against a brick wall.  The cluster
seems to be seeing around 13.5volts when the van is running and all of the
other lights, etc. on the cluster seem to be working fine.  Yet the battery
light won't go out.

I think originally this van used to have the oxy light and box, but the box
is no longer there and the newer instrument cluster doesn't have the oxy
light in it.  I guess what I need to know is exactly what the light is
looking for as an input to turn the light out.  I have never been
completely clear as to exactly what I should be seeing from the blue wire
that goes to the alternator since this is also the wire that is controlling
the light.  Should I see a voltage from this wire?  Is it a ground
instead?  If someone could explain what this blue wire does that would help
me out a lot.

Sincerely,
Ken Wilford
John 3:16
www.vanagain.com