Go Back   Ford Truck Enthusiasts Forums > Older, Classic & Antique Trucks > 1973 - 1979 F-100 & Larger F-Series Trucks
Sign in using an external account
Register Forgot Password?


1973 - 1979 F-100 & Larger F-Series Trucks Discuss the Dentsides Ford Truck

Welcome to Ford-Trucks Forums!
Welcome to Ford-Trucks.com.

You are currently viewing our forums as a guest, which gives you limited access to view most discussions and access our other features. By joining our 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 the Ford-Trucks Forums community today!





 
Reply
 
 
 
 
LinkBack Thread Tools Search this Thread
  #1  
Old 10-03-2011, 01:17 PM
saxtonj's Avatar
saxtonj saxtonj is offline
Senior User
 
Join Date: Aug 2000
Location: Carthage TX
Posts: 124
saxtonj is starting off with a positive reputation.
Heater not blowing hot

I have a '78 F150 Explorer with 400 and factory A/C.

My heater won't blow hot air, it will blow lukewarm/room temperature at best. The fan is working fine. I have hot water coming into the firewall and return hose gets hot too. Is there a vacuum operated door or something that I should suspect? Heater has worked great for the past 33 years.

Any ideas?
Reply With Quote
  #2  
Old 10-03-2011, 02:24 PM
SCRAPHEAP51's Avatar
SCRAPHEAP51 SCRAPHEAP51 is offline
Senior User
 
Join Date: Aug 2010
Location: Oregon
Posts: 391
SCRAPHEAP51 is a splendid one to beholdSCRAPHEAP51 is a splendid one to beholdSCRAPHEAP51 is a splendid one to beholdSCRAPHEAP51 is a splendid one to beholdSCRAPHEAP51 is a splendid one to beholdSCRAPHEAP51 is a splendid one to beholdSCRAPHEAP51 is a splendid one to behold
Maybe the heater core is partially blocked, maybe only a few tubes free to allow flow thus only getting warm and not hot? What about the levers operating the doors are they free and working? just guessing here.
__________________
Build Page
Reply With Quote
  #3  
Old 10-03-2011, 04:13 PM
starwriter starwriter is offline
Junior User
 
Join Date: Jan 2008
Posts: 79
starwriter is starting off with a positive reputation.
I can think of a few things it could be.
1) You can reverse the heater hoses believe it or not, I didn't at first. You may need to switch them.
2) There is a cable running from your temperature slide/switch on the dash to a vent. This can come unhooked and allow very little warm air into the cab.
3) Surrounding the heater core is some weather stripping, it breaks down over time and allows air to flow around instead of through the heater core.
Reply With Quote
  #4  
Old 10-03-2011, 04:19 PM
hasteranger's Avatar
hasteranger hasteranger is offline
Postmaster
 
Join Date: Mar 2010
Location: West Virginia
Posts: 4,062
hasteranger is a name known to allhasteranger is a name known to allhasteranger is a name known to allhasteranger is a name known to allhasteranger is a name known to allhasteranger is a name known to all
id say its the door that directs the air over the heater core.. its controlled by the temp slide. Its not easy to get to.
__________________
'04 4wd Excursion Limited PSD tow rig.
78 4wd Supercab on RCLB frame with 5' flatbed,frame bobbed 6", 460/C6/NP203/205 doubler, 05 superduty one tons, cage arms, deaver 6" springs
Reply With Quote
  #5  
Old 10-04-2011, 08:06 AM
saxtonj's Avatar
saxtonj saxtonj is offline
Senior User
 
Join Date: Aug 2000
Location: Carthage TX
Posts: 124
saxtonj is starting off with a positive reputation.
The temperature slide moves good with slight resistance which might indicate that the cable is not off or broken and is still working a door or something.

I will try changing the hoses first, but if that doesn't work I guess I will have to pull the under dash unit and perform exploratory surgery...
Reply With Quote
Old 10-04-2011, 08:06 AM
 
 
 
Reply

Go Back   Ford Truck Enthusiasts Forums > Older, Classic & Antique Trucks > 1973 - 1979 F-100 & Larger F-Series Trucks

Tags
79, blows, ford, heater, hot, room, temp, truck, warm

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
heater not working at idle jwheatley20 6.0L Power Stroke Diesel 36 11-15-2013 05:51 AM
2001 Ford Expidition aables182 Expedition & Navigator 6 03-10-2013 03:02 PM
Heater dosnt work but AC does??? ljemmer465 Excursion - King of SUVs 12 02-02-2013 05:29 PM
98 Navi - Heater blows hot all the time even with A/C on joners Expedition & Navigator 6 05-24-2010 06:07 PM
Heater problem apb76 Bronco II 2 04-15-2005 11:51 PM



All times are GMT -5. The time now is 03:51 PM.


Powered by vBulletin® Version 3.8.7 AC1
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Advertising - Terms of Use - Privacy Statement - Jobs
This forum is owned and operated by Internet Brands, Inc., a Delaware corporation. It is not authorized or endorsed by the Ford Motor Company and is not affiliated with the Ford Motor Company or its related companies in any way. FordŽ is a registered trademark of the Ford Motor Company.

vbulletin Admin Backup