I think it's designed to do that. I think you mean it
switches outlets continuously. My 95 S10 did. I thought
it was kinda funky. It may also depend on whether you have
it set to recirculate or whether you use "normal" mode.
And also which outlet setting you use.
Vacuum leak between the reservoir and the control head in the dash. When
you step on the throttle the vac level drops and the controls switch to
default position. Could also be a bad check valve on the reservoir as
Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here.
All logos and trade names are the property of their respective owners.