Air bag light on '91 CQ

[James Desveaux <desveaux@ucla.edu>]

I know this subject has been bandied about on the list before.  I have a
friend with a '91 Coupe Quattro with just under 90k on it.  He's had the
airbag recall done at the dealer.  In recent weeks, he's noticed that the
airbag warning light takes sometimes 2 or 3 minutes to go out.

Any quick and dirty ideas on the cause?  

TIA.

- Jim

p.s. I've never encountered this problem on my car, so I'm uninformed on
this one.