A/C Blowing through the Defrost Only

[tgraham320]

I have a 1998 Windstar thats A/C blows cold as ice. One problem, it only blows through the Defrost vents not the vents in the dash. The Rear A/C does the same but only through the Floor vents.

I replaced the Control switch in the dash that changes the mode of the A/C but not the rear control switch.

Before I spend another 30 bucks to be disappointed is the rear fan switch a possible culprit or am I waisting my time and money?

I also checked all the vaccum lines and connections that I could see and all of them looked to be in decent shape, no breaks or cracks.

Any help would be appreciated....

[Andrew1941]

I know you said you checked, but I would check again on the vacuum lines. The vacuum is what moves the door that directs the air to anywhere other than defrost. If there is no vacuum to move the door, by gravity if falls back to defrost and stays there.

On e thought that I just came up with is can you direct the heated air anywhere other than defrost? If you can, then that would clarify that it is not a vacuum/gate problem.

I have the Ford DVD manual for 2000 to 2003. If you have no success, let me know and I will try to see if there is anything there....should be pretty similar to a 98.

[mundy5]

tgraham320,

I've checked my 2001-03 DVD and saw that all the issues are vacuum related. I'd be glad to send you a Pdf of that section but it might not be the exact setup with your '98. maybe someone with a '98 model can chime in here.

[tgraham320]

I wasn't sure how to "test" the vacuum lines but I did visually inspect them and didn't see any loose connections or cracked lines. I blew through the ones I could get loose to see if maybe they were clogged and didn't find anything there either.

I checked the heated air and it does the same thing. Only through the defrost.

That would be awesome if you could send a pdf of that section. Even if its not exactly like my set-up it may give me something else to go on as I'm not real confident on the whole vacuum set-up

[tgraham320]

Big Thanks to the both of you guys!!!!

With your schematic of the vacuum system mundy I was able to trace the flow of air through all the major components until I got to the Rear blower control switch. I could hear the vacuum sucking through the connector so I stuck my thumb over the hole to stop the vacuum and Whalah! Air through the vents!

I promptly ran to the nearest O'reilly and picked up the switch ( Part # YH-1465) which is the rear blower swith, replaced it and it worked like a charm!

Took all of 5 minutes and $22.00 to get the A/C blowing cold again

[mundy5]

congrats! glad to be of help.

[kckndrgn]

All,
I just found this forum after fixing my 171/174 codes from leckemby.net. I'm now experiancing the same thing with my blower - only goes through defrost. I imagine I missed a vent line some somewhere, but I cannot find it.

Can anyone point me to the right area to look? I could have sworn that all connections were checked and re-checked during reassembly, but I guess I missed on.

Thanks for any help!

Ryan

[Andrew1941]

I'm at work or I would send you the schematic, but maybe PM the Mundy5 and he can forward you the same PDF. I am not familiar with under the dash vacuum lines because I have not had to trace it out before, but it should pass through the firewall on the passenger side (red plastic line) and head towards the centre console, up to behind the controls. Easy enough to get them out of the console. Remove all the screws around the console plastic cover, pull the radio (need a tool - about $10 at Wallmart) get the last screws which are behind the raido and pull the cover and controls out. In the engine compartment, the line is on the passenger side under the cowel (near the top) where you can't see it well. If you remove the windsheild wipers, then the cover, then the cowel, you have full access to the lines. The line should conenct to a plastic box on the side of the air intake for the heating system. From there it will head over to the manifold. The leak will be somewhere along that path. Good luck. Just a thought, not that I have tried it, but with the engine off, you could locate the line at the manifold, pull it off. Without the engine running, have someone blow air into the line and then listen for the leak. Maybe you will hear where it is coming from and then you know where to go looking? Might be hard though since the lines are very small, but it wouls only take a minute or so to find out...

[kckndrgn]

Thanks,

I was able to figure it out. I found another post were someone did the same work I did and had the same problem.

There is a red vacuum line coming off the lower have of the intake plenum that goes to a "T" Part of that "T" goes to a "box" on the firewall, that's were the line became disconnected.

I was able to get is back on and everything works now.

Thanks for your help.
Ryan