A/C blows only through the defrost vents.

[stangohr]

Hi folks,

I have a '97 Aerostar. A/C blows plenty cold by there is a problem with the mixing door and it blows only through the defroster vent. Thinking that it might be the dash switch I bought a new/used one. Problem is not there. Rather, there is no vacuum in one of the lines that connect to the dash selector.

I know this because I have a '94 Aerostar with the same dash. I pulled that one apart and had vacuum in the same line. Obviously there is a vacuum leak but before I take the dash apart and probably the evaporator box I'd thought I'd ask if any of you had similar probs.

Thanks!

Best,

Stangohr
Aiken, SC

 

[DjDom]

It sounds to me like the system that controls where to blow is stuck.
However, you're talking about an aerostar, and this is the Explorer Section.

A mod will move your post to here:
http://www.explorerforum.com/forums/forumdisplay.php?f=146

 

[BrooklynBay]

Welcome to this forum! I've moved your thread into the Aerostar section. Check the hard plastic vacuum line under the hood which is plugged into a check valve & servo piston. The plastic usually cracks near the rubber boot which is plugged into the servo piston. This area is between the blower motor housing assembly, and the engine area.

 

[rv4fun]

I've had a couple vacuum leaks at the connector to the vacuum motor right over the engine - looking under the hood, it's on the left of center. Try pulling the vacuum line off the vacuum motor. I test mine by turning off the engine and connecting the vacuum lines to a handheld vacuum pump. You should be able to suck a vacuum and hold it. If the lines aren't leaking, you could have a leak in the diaphragm of one of the vacuum motors - test them with the hand held vacuum pump too.