thermal fuse, blower motor and fan controller woes - JeepForum.com
 
LinkBack Thread Tools
post #1 of 7 Old 07-02-2010, 05:28 PM Thread Starter
Zamboni0neXJ
Registered User
1999 XJ Cherokee 
 
Join Date: Jan 2010
Location: St Cloud, MN
Posts: 21
thermal fuse, blower motor and fan controller woes

I have replaced everything mentioned above and some twice. Something is making the load on the thermal resistor enough to make it fail and go into the high only setting. On top of that, the controller, under heavy load (ac mainly) shuts off and on every 4 seconds. Blower motor is brand new, thermal resistor was brand new. Replace the controller unit and the plug on the drivers side. Plug was melted and damaged. Haven't taken it apart to see if it got nuked yet.

Please send any and all ideas my way. I am brain shot now.

Zamboni0neXJ is offline  
Sponsored Links
Advertisement
 
post #2 of 7 Old 07-02-2010, 09:19 PM
BrunoS
Registered User
 
Join Date: Aug 2004
Location: South Bay Los Angeles, CA
Posts: 2,534
sounds like case of high voltage under the hood.

1) what year xj is this?

2) what is the engine running battery voltage?

3) common failure part in 96 and older xj was the blower speed switch, which got dirty/hot spots/failed at the wiring harness connector (would smell like melted plastic at the dash when the blower was on hi speed).

4) if that speed switch connector is fried (like mine was) then you may have a short at that point which is causing your problems;

5) or your alternator is overcharging (like 16 volts or more) and this is yet another thread.

Newly Painted! Emerald Green '96 XJ 4x4 4.0 HO 5-spd
3" Lift + 31" Tires / D35 TracLok / NP231
Drilled out Stock Airbox / Gauge Cluster Upgrade
Magnaflow Muffler / High-flo Cat / MSD Coil
BrunoS is offline  
post #3 of 7 Old 07-03-2010, 09:19 AM Thread Starter
Zamboni0neXJ
Registered User
1999 XJ Cherokee 
 
Join Date: Jan 2010
Location: St Cloud, MN
Posts: 21
I forgot to fill out my profile sorry. Its a 99 sport.

Voltage has been normal. I did smell what seemed to be an odd smell after replacing the controller. I am leaning towards it being a bad controller, but never thought about a short. Thanks, I will begin my painful search.
Zamboni0neXJ is offline  
post #4 of 7 Old 07-03-2010, 09:42 AM
myriad360
Registered User
2008 WJ 
 
Join Date: Oct 2006
Location: Moscow, ID
Posts: 551
Check the fuse values in your fuse box if this circuit is included, something is running hotter than it should. X 2 above, if the fuses are correct, you probably have a short somewhere. Ammeter?

Great XJ Troubleshooting/mod sites list: http://myriad360.x10hosting.com/blog/?cat=9
2001 Jeep Cherokee 4.0 L Limited, White. Bought in Grangeville, ID 06/11/08. Stock everything.
1998 Jeep Wrangle 4.0 L, Green. Bought in Nampa, ID 02/21/09
1988 Jeep Cherokee 4.0 L, White. Bought in Vancouver, WA in 2003. 1st Jeep, White. Bought with 3" lift, added Pacesetter header and 40 series Flowmaster
myriad360 is offline  
post #5 of 7 Old 07-04-2010, 07:53 AM Thread Starter
Zamboni0neXJ
Registered User
1999 XJ Cherokee 
 
Join Date: Jan 2010
Location: St Cloud, MN
Posts: 21
I think I tracked the short down. It was in the blower motor itself. Resistor was still good. Swapped out blower motor and no problems so far.
Zamboni0neXJ is offline  
post #6 of 7 Old 07-04-2010, 01:31 PM
myriad360
Registered User
2008 WJ 
 
Join Date: Oct 2006
Location: Moscow, ID
Posts: 551
Quote:
Originally Posted by Zamboni0neXJ View Post
I think I tracked the short down. It was in the blower motor itself. Resistor was still good. Swapped out blower motor and no problems so far.
Didn't you already replace the blower motor?

Great XJ Troubleshooting/mod sites list: http://myriad360.x10hosting.com/blog/?cat=9
2001 Jeep Cherokee 4.0 L Limited, White. Bought in Grangeville, ID 06/11/08. Stock everything.
1998 Jeep Wrangle 4.0 L, Green. Bought in Nampa, ID 02/21/09
1988 Jeep Cherokee 4.0 L, White. Bought in Vancouver, WA in 2003. 1st Jeep, White. Bought with 3" lift, added Pacesetter header and 40 series Flowmaster
myriad360 is offline  
post #7 of 7 Old 07-04-2010, 06:27 PM
Whackmaster
Registered User
1999 XJ Cherokee 
 
Join Date: Aug 2008
Location: Huntsville,Texas
Posts: 126
I was having the same problem with my 99...After replacing the blower motor twice it worked fine for about 3 months but it is back to the old way...I have given up............

I LOVE THIS STUFF
Whackmaster is offline  
Reply

Quick Reply
Message:
Options

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

Password:


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



Email Address:
OR

Log-in









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
need help, blower motor or fuse? MxAjN XJ Cherokee Technical Forum 12 02-20-2009 05:02 PM
'92 Engine Controller Fuse rstarch345 XJ Cherokee Technical Forum 1 05-31-2007 08:36 AM
Blower motor maxi fuse.... bigkiang XJ Cherokee Technical Forum 1 11-04-2005 08:05 PM
HELP! Blower motor, wiper motor dead surferri07 XJ Cherokee Technical Forum 0 10-26-2004 07:13 AM
Thermal Fuse location on 98 XJ? cmassey_2001 XJ Cherokee Technical Forum 18 07-13-2004 11:19 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