> 
> My OXS and Alt. lights come on together too when there isn't enough
> voltage.  I found my problem was the alternator pully slipped. You might
> just need to check your belt and your charging system in general.
> 
> I think it's just afreak thing that both lights go on when I found it to
> be a charging problem.  Oxy Sensor was fine.
> 
> Hotch 
> 86 GL
> Philly
> 
Hotch and others,
It's not just a freak thing.  The reason both lights come on together is
because both are on the same circuit.  You will notice that both lights
go out at the same instance when the van is started and the engine
revved.  

The OXS light has nothing whatsoever to do with the oxygen sensor.  It
comes on every so often (I forget how many miles it is).  You know that
black box that's in line with the speedometer cable?  Well every certain
number of miles, that box closes a switch which turns the OXS light on.
Same as in my '81 with the EGR light.  To reset it, you find that box
and push the little white button and the light goes off for a few more
miles.  With my EGR light it's every 15,000 miles.  The natural
consequence of both lights being on the same circuit is that the OXS
light will come on if the alt. light comes on (same as when you turn the
key on but don't start the engine).  Doesn't mean anything's wrong with
the oxygen sensor but it's not a coincidence either.

Sean