AC air coming out of defrost vents

[Kneale Brownson]

Have you tried bumping the box while applying a reliable vacuum with 
something like a MightyVac?


At 08:08 PM 08/13/2001 -0600, Steve Sherman wrote:

>Bruce:
>
>This may be some small part of the problem.  The first mile or so of my
>commute is on dirt roads, which supply more than enough bumps.  Sometimes the
>bumping will cause the air to switch to the dash. (Much less now that I have
>switched controllers to my "spare")  However most often it does not, and even
>hitting the controller directly does not have an effect in most cases.
>
>While I fully agree with your design comments, I have checked (by mouth) and
>all the the 4 lines in the controller do seal when they are not activated.  So
>Unfortunately I don't think this is what is going on in my case (at least this
>time).
>
>Steve
>
>Bruce Toski wrote:
>
> > The small pintle check valves located in the four 4 ? electromagnetic
> > solenoids located inside the controller which is mounted behind the glove
> > compartment are not spring assisted.  This oversight, IMHO, causes erratic
> > operation of the vacuum solenoids.  Next time air comes out the defrost,
> > kick, .............er, tap the controller and see if air starts coming out
> > of the chest vents.........
> > This is assuming there are NO vacuum leaks in any of the vacuum air valves
> > that control air flow throughout the system.  Curious to know if this
> > helps.......
> >
> > Bruce Toski
> > 2361 SW 36th Terrace
> > Fort Lauderdale, FL 33312-4291
> > Phone (954) 583-4191
> >
> > 72 and 73 Audi 100LS sedans
> > 86 and 91 Audi 5000/100 sedans
> > 74 Mazda REPU (Rotary Engine PickUp)
> > http://clubs.yahoo.com/clubs/audi100c1series