I have a 1990 S-10 Blazer, and since yesterday, the lower vent (in the middle front floorboard) will not close. Its not blowing hot air or anything, but now when the AC is on max, it doesn't blow nearly as hard out of the dash vents. I know this is vaccuum operated, but I don't even know where to begin to look for the auctuator or vaccuum line running to it. Can anyone offer any help?

Thanks
Jeff

 

Try www.s-series.org.
Most likely it's a bad vacuum line going to the control from the engine, or a worn out control(my guess). Check the connections on the back of the control, and then check for vacuum(engine must be running). It could also be that something fell into the ductwork and is blocking the flapper, but I still would check out that control first. They tend to wear out.



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82 camaro--original steering wheel, brake/gas pedals, seats--everything else modified
82camaro