Quantcast 1984 F350 4x4 6.9 ac stuck on defrost - Ford Truck Club Forum




Home






Forum






Gallery






Garage






Blog






Arcade






Settings






New Posts






TOTM






Vote




Remember Me?
       Join for free!




Search






How-To's






Unanswered






FTC Toolbar






Social Sites






Register




 
Ford Truck Club Forum > FORD F-250 | F-350 SERIES | SUPER DUTY > 1948-1986 Ford F250 | F350



Welcome to FordTruckClub.net
Welcome to FordTruckClub.net, the internet's premier Ford truck community! You are currently viewing our boards as a guest which gives you limited access to view discussions and access other forum features. By joining our free online community you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is fast, simple, and absolutely free so please, join our community today!

Forgot your password? click here.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 

 
Thread Tools Display Modes
  #1  
Old August 1st, 2017, 12:00 PM
pappywith4's Avatar
pappywith4 pappywith4 is offline
 

Join Date: Aug 2017
Location: Lake sam rayburn
Posts: 3
Likes : 0
Liked 0 Times in 0 Posts
Default 1984 F350 4x4 6.9 ac stuck on defrost

Like the title says for some reason my blower only blows out of the defroster!
I change settings but stays the same.
Can some one point me in the right direction?
thanks
  #2  
Old August 1st, 2017, 10:53 PM
glc's Avatar
glc glc is offline
 

Join Date: Jul 2012
Location: Joplin MO
Posts: 765
Likes : 1
Liked 22 Times in 19 Posts
Default

I don't know when Ford started using vacuum operated HVAC controls, but on later model trucks this can caused by the lack of vacuum to the system. Trace back the vacuum lines, you will probably find one missing, disconnected, or broken. Another possibility is a stuck blend door or bad blend door actuator. The dash control head could be shot.

If it's cable operated, the cable could be disconnected or broken.

Note that diesels have a vacuum pump, there is no manifold vacuum like with gassers.

2003 F-150 XL RCSB 2wd 4.2 5 speed 3.55 LS
  #3  
Old August 2nd, 2017, 06:25 AM
JSoko's Avatar
JSoko JSoko is offline

 

Join Date: Jun 2009
Location: Northwest Georgia
Posts: 14,677
Images: 615
Likes : 29
Liked 133 Times in 115 Posts
Default

good advice above ^^

I had a mouse make a nest and block the blend door
look for dropping on floor board and under hood to rule this out


For Those Who Fought For It...
Freedom Has A Taste The Protected Will Never Know.













Last edited by JSoko; August 2nd, 2017 at 06:45 AM.
  #4  
Old August 11th, 2017, 09:08 AM
pappywith4's Avatar
pappywith4 pappywith4 is offline
 

Join Date: Aug 2017
Location: Lake sam rayburn
Posts: 3
Likes : 0
Liked 0 Times in 0 Posts
Default

thanks to everyone who replied!
I found where a vacum line was spliced and when I squeezed the joint the vent worked so I found the problem!
I will put a gasket sealer around the ends of the connections and that should take care of it. Thanks again john


Thread Tools
Display Modes


(View-All Members who have read this thread : 4
glc , harrison28 , JSoko , pappywith4

Similar Threads
Thread Thread Starter Forum Replies Last Post
Heater won't switch from vent to defrost BigBlue79 1980-1986 Ford Bronco
12 July 8th, 2013 05:06 PM
1984 Mustang GT ?'s JSoko Ford Cars 7 June 24th, 2012 11:24 AM
How to Change the PVC Valve on a 1984 Ford F-150 JSoko Garage Talk: Shop Class 101 0 July 15th, 2011 09:27 AM
Now this is stuck! BigT67 General Discussion
5 January 27th, 2010 04:44 PM
I got stuck :( SS FatMan General Discussion
27 November 30th, 2009 10:00 AM

Tags
1984 , 4x4 , defrost , f350 , stuck

Forum Jump









FordTruckClub.net is not authorized, endorsed or affiliated with the Ford Motor Company
or any of their subsidiaries. Ford® is a registered trademark of the Ford Motor Company


Powered by vBulletin® Version 3.8.6 Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.