Help with Cab Fan 2003 Rubicon - Rubicon Owners Forum
  • 1 Post By aeroshots
  • 1 Post By BobsLJ
  • 1 Post By ArkansasRubi
LinkBack Thread Tools
post #1 of 6 (permalink) Old 01-23-2019, 02:56 PM Thread Starter
Rubi Noobie
Join Date: Jan 2019
Posts: 4
Help with Cab Fan 2003 Rubicon

Good day.

I have a 2003 Rubicon that is pretty in much showroom condition, being garaged since new, with undet 10K miles.

Since inheriting this jeep from my father I have noticed the cab fan is always running on low, unless turned up to a higher speed. Heater and air work fine, but looking under the hood while the jeep is running, it appears the air pump clutch is always engaging and un-engaging. Is this normal on a jeep that there is no way to fully shut off the fan, or do I have a problem?

Any suggestions what the problem could be, if there is a problem?

Thank you
Attached Images
File Type: jpg Jeep 1.JPG (86.8 KB, 52 views)
File Type: jpg Jeep2.JPG (91.6 KB, 54 views)
Barkoff is offline  
Sponsored Links
post #2 of 6 (permalink) Old 01-24-2019, 10:11 AM
johncanfield's Avatar
Join Date: Oct 2010
Location: Texas Hill Country
Posts: 10,427
Hi and welcome! I don't think the AC compressor clutch should be engaging and disengaging like that. If you turn the air selector to off, nothing should be running. Download the factory service manual (FSM) and go through the troubleshooting. I think the AC clutch is controlled by the powertrain control module (PCM). Search here for "FSM" - I think you'll find a link or an idea of where to get the FSM.

John - WB5THT
2006 LJ, not stock
johncanfield is offline  
post #3 of 6 (permalink) Old 01-24-2019, 11:26 AM
Rubicus Maximus
aeroshots's Avatar
Join Date: Sep 2010
Location: Gulf Breeze
Posts: 589
Welcome and cool beans on the mint Jeep. I'm sure it means a lot for you to have your dads Jeep.
johncanfield likes this.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
aeroshots is offline  
post #4 of 6 (permalink) Old 01-24-2019, 02:21 PM Thread Starter
Rubi Noobie
Join Date: Jan 2019
Posts: 4
Thank you.

Think I'll try swapping out the relay first, saw a clip where a person's headlights would not turn off becasue the relay went bad. Start with the easy efforts,
Barkoff is offline  
post #5 of 6 (permalink) Old 01-24-2019, 03:07 PM Premium
BobsLJ's Avatar
Join Date: Apr 2012
Location: Palm Desert, CA
Posts: 1,554
If the a/c continues to cycle frequently you probably need to add Freon. Low Freon will cause that issue.
If the system is turned off (O position on the heat/ac control), nothing should be on.
As I recall, the ac compressor will cycle when you select the defrost setting to help control the humidity.
IMO, relay is not your issue.
Also, as soon as you turn the system from the O setting, the fan speed you have selected will come on.
johncanfield likes this.

2006 Turbo LJ Rubicon, Red
BobsLJ is offline  
post #6 of 6 (permalink) Old 01-25-2019, 03:12 PM
Rubi Noobie
ArkansasRubi's Avatar
Join Date: Jul 2018
Location: Ward, Arkansas
Posts: 90
Welcome aboard. Nice jeep for sure.
I second the low freon being a possible cause of A/C clutch cycling. Was my problem last year.
As far as the cabin air fan, I had another make vehicle with similar issue. The fan selector switch itself was the issue.
Good luck with the trouble shooting.
Hopefully something from someone here helps you solve the issues.
johncanfield likes this.

ArkansasRubi is a 2006 TJ Rubicon severely mistreated but on the mends. Nothing enough money can't fix!
ArkansasRubi is offline  

Quick Reply

Register Now

In order to be able to post messages on the Rubicon Owners Forum 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 email address for yourself.

Email Address:


Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page

Similar Threads
Thread Thread Starter Forum Replies Last Post
WAS> Griffin radiator/Spal fan install NOW> Mishimoto & RF-39 fan install johncanfield Rubicon Tips... Techniques and Write ups 111 11-03-2014 09:38 AM
Seven blade fan and HD fan clutch Norminator TJ Drivetrain and Horsepower 3 10-26-2008 12:00 PM
Clutch fan VS Electric Fan racingperf TJ Drivetrain and Horsepower 9 04-19-2008 09:26 PM
Winch +Electric Fan +Both on = Blown Fan fuse gregert12 TJ Communications And Electronics 10 12-12-2005 08:00 PM
will 2000 Fan clutch fit 2003? s3rous General Tech 2 04-10-2005 09:12 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 On
Pingbacks are On
Refbacks are On

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