95oldsVan Posted June 21, 2006 Report Share Posted June 21, 2006 Whats the cure for this? Every setting works except the defrost.Ill get air coming out the front dash vents,front and bottom,or the bottom or etc depending on setting but barely anything comes out from top of dash when knob is in defrost position.Didnt know it did this until the other day when it rained for a while and the windshield began fogging over. Is there a mix door I need to adjust or is it a vacuum problem? Any ideas is appreciated.A fgew more bugs worked out and the car will be like new...Thanks! Quote Link to comment Share on other sites More sharing options...
Supreme Cutlass Posted June 21, 2006 Report Share Posted June 21, 2006 Whats the cure for this? Every setting works except the defrost.Ill get air coming out the front dash vents,front and bottom,or the bottom or etc depending on setting but barely anything comes out from top of dash when knob is in defrost position.Didnt know it did this until the other day when it rained for a while and the windshield began fogging over. Is there a mix door I need to adjust or is it a vacuum problem? Any ideas is appreciated.A fgew more bugs worked out and the car will be like new...Thanks! My guess is a vacuum problem if there isn't any air coming through, look for a pinched line. It might also be the switch that all the lines hook into Quote Link to comment Share on other sites More sharing options...
slick Posted June 21, 2006 Report Share Posted June 21, 2006 Usually if it is a vacuum problem, it will only blow out of the dash. It could be that the "doors" or "gates" or whatever the hell you want to call them aren't moving all the way to blow to the vents, could be a faulty switch, it's really hard saying. Quote Link to comment Share on other sites More sharing options...
95oldsVan Posted June 30, 2006 Author Report Share Posted June 30, 2006 Thanks for the replies before...I got around to working on the dash today and checked all the vacuum lines...didnt find anything wrong. Could be the switch,who knows...but is there a way to test the system like using a vacuum pump? is there a number I should be seeing on the guage? Or use the pump to try and manually move the door? I noticed there are 2 small vacuum cannisters inside the dash on both sides...they have linkage arms that appear to be the mix door mover....Is there any way to test and see if these are bad? Should they hold vacuum if I unplug thelines and put a vac pump on there? Thanks for any ideas. Quote Link to comment Share on other sites More sharing options...
95oldsVan Posted June 30, 2006 Author Report Share Posted June 30, 2006 Well,did a bunch of checking today...seems to be the mix door wont move enough to allow the air to go out the defroster full blast...I even unplugged the vacuum switch and made a 3 way vac T and jumped the lines with extra vac tubes and tried to manually vac open the door and the vacuum suction is very strong at the purple line which comes from the engine bay.That moved the door linkage some but not enough. I dont know if the door is jammed or something got stuck inside...I can see the vacuum linkage move up and down on both sides,but wont move the door fully. Cannot find a vac leak anywhere. Turns out the switch itself seems fine...turning the switch,can see the door linkage moves but stops before it allows the air to go thru defrost. If there was a leak,more than likely it would move the linkage and then release it back but doesnt..it holds it steady,just wont move anymore after a point. Gonna go see if I can see in there if there something jamming the door. But if this rings a bell to a problem of something I can fix or adjust,any ideas is appreciated. Quote Link to comment Share on other sites More sharing options...
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