hello folks, I have found a problem in my delta 88 about the ventilation air blow, in the sense that moving the air blow direction lever the air blows always from the same point, some thing must be happened, as the leverage it worked as it should, at least one of the last times I needed to use it.
the system has two levers, the one that moves from cold to warm it works good, the one that moves the blow seems not working.
Moving the lever on the " heat" position the air must blow from the upper grill of the dashboard and from the lower hose in the bottom.
then, there are other two positions: "bi-level, and defrost", but air does not blow on the windscreen, and does not work the de-fog and the de-frost.
What could be happened? what must remove to work on it?

 

Your car uses engine vacuum to operate various vacuum diaphragms on the HVAC box under the dash. These diaphragms move the internal doors that control where the air comes out. The most likely cause of your problem is a vacuum hose that has come loose or cracked under the hood. There is a hose from the intake manifold to a round vacuum reservoir on the firewall, and from there to the HVAC controls on the dash. The dash controls have a vacuum switch that routes vacuum to these various diaphragms depending on where you have moved the levers. If air only blows out the bottom vent no matter the position of the lever, this indicates that there is no vacuum to the system. Look for a disconnected hose.

 

Hi Joe, thank you for the suggestion, yeah, it's possible that some vacuum it has not been positioned as it should, in effect we worked on the engine last year, and we were not sure to have posditioned all the vacuum hoses in the right place. There is a vacuum diagram on the front end under the hood, but it's worn and uncomprehensible and so some hose could be gone in the wrong place. then, you must explane me what is the firewall and what the HVAC. then, for last, where is it possible find a vacuum diagram? thank you for your willing
Beppe

 

 

thank you Joe, hopethis helps to solve the problem
Beppe