heater help: not the usual heater problem - JeepForum.com
LinkBack Thread Tools
post #1 of 3 Old 12-05-2010, 05:51 PM Thread Starter
doug davis
Registered User
1997 TJ Wrangler 
Join Date: Apr 2007
Location: new jersey
Posts: 16
heater help: not the usual heater problem

I have a 97 4 cyl TJ with no AC.

The heat is marginal so I did the normal things: flushed the core, changed the thermostat, checked the operation of the diverter, mixture flap etc.

What I noticed is that when the mixture flap (temp control lever) is on full hot, the airflow through the outlets is severely restricted. Almost no air flows at all (what does flow is warm, however) When the temp lever is on cold, the blower moves massive amounts of air, probably triple the amount.

So my feeling is, the OUTSIDE air passage (not the internal pipes where the water flows) of the heater core has become blocked with debris somehow and airflow across it is very limited, thus producing very little heat.

Has anyone ever heard of this and know how to fix it without dismanteling the entire heater box? I was thinking about taping off all the dash outlets but one and blasting air backwards through the system with a backpack leaf blower to try to unblock the core.


Doug Davis

doug davis is offline  
Sponsored Links
post #2 of 3 Old 12-05-2010, 06:47 PM
Registered User
2006 WK 
Join Date: Jul 2008
Location: Sioux Falls
Posts: 3,271
You could try removing the heater blower assembly and seeing if there is a pile of leaves and such inside that area. It's fairly easy to do this, just pull out the battery and it's right there.
durango-bob is offline  
post #3 of 3 Old 12-06-2010, 05:34 AM Thread Starter
doug davis
Registered User
1997 TJ Wrangler 
Join Date: Apr 2007
Location: new jersey
Posts: 16
doug davis is offline  

Quick Reply

Register Now

In order to be able to post messages on the JeepForum.com forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid e-mail address for yourself.

Email Address:


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page

Similar Threads
Thread Thread Starter Jeep Forums Replies Last Post
Reverse heater lines at intake 4.2 (front to heater core/ rear to bypass port) Chris Aunchman YJ Wrangler Technical Forum 1 07-27-2010 01:16 PM
YJ Heater Core and Heater Motor Replacement?? Boston Mangler YJ Wrangler Technical Forum 11 11-29-2009 08:31 AM
heater motor upgrade (dont worry its not the usual question) speepdaedeesi YJ Wrangler Technical Forum 10 09-13-2009 08:48 AM
heater problem (not the usual) bently TJ Wrangler Technical Forum 1 05-07-2008 11:31 AM
heater problem StuckInMud94 TJ Wrangler Technical Forum 1 02-03-2007 03:53 PM

Posting Rules  
You may post new threads
You may 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 Off
Trackbacks are Off
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome