A/C Blower fan will not turn off - Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum



Welcome Enthusiast! If you already own a Chevy TrailBlazer or GMC Envoy or perhaps thinking of purchasing such a vehicle, then you have come to the best TrailBlazer and Envoy site on the net! Rainier, Bravada, Ascender, and 9-7x owners welcome too!

You are currently viewing our site as a guest which gives you limited access to view most discussions and access our other features. By joining our free community you will have access to search and post topics, communicate privately with other members, respond to polls, upload content, and access many other special features. Registration is fast, simple and absolutely free so please, join our community today!

If you have any problems with the registration process or your account login, please contact contact us.
Join Today!
Go Back   Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum > 2002 - 2009 TrailBlazer/Envoy Tech > 02-09 General Tech Q&A > General

General If it doesn't fit in any other forum

TrailVoy.com is the premier GMC Envoy Forum on the internet. Registered Users do not see the above ads.
Reply
 
Thread Tools
  #1  
Old 06-03-2009, 04:26 PM
lifl2003 lifl2003 is offline
Junior Member
 
2003 Chevy TrailBlazer LT EXT
Pewter Metallic 4.2L I6 4X4
Join Date: Jun 2009
Location: Long Island, NY
Posts: 7
A/C Blower fan will not turn off

Hi all,

My 03 TB's a/c fan blows on high and will not turn off even when the power is turned off. I have been reading other similar thread and many people said that it sounds like the "speed control module". Could this be my problem.

I brought it to my local service station today and he said the part from GM is like $440.00 plus labor. I looked on the web and the speed control module is about $100.00. Am I being ripped off or could he be correct?
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2  
Old 06-03-2009, 05:38 PM
rbarrios's Avatar
rbarrios rbarrios is offline
TrailVoy Guru
 
2003 Chevy TrailBlazer LS
Pewter Metallic 4.2L I6 2WD
Join Date: Sep 2004
Location: west covina
Posts: 5,267
have you pulled the fuse for it?

if not- pull it- and then read up some more on here.
I think Ive seen similar post before.
__________________
2013 Equinox-3.6L DI- Best MPG 35
2010 Traverse-3.6L DI Best MPG 31.3
2003 Trailblazer LS 165,000 miles- Best MPG 24
Reply With Quote Quick reply to this message
  #3  
Old 06-03-2009, 07:17 PM
RayVoy's Avatar
RayVoy RayVoy is offline
TrailVoy Guru
 
2009 Chevy Avalanche LTZ
Black 5.3L V8 4X4
Join Date: Jul 2006
Location: Atlantic Canada
Posts: 6,431
Yep, your being ripped big time.

The problem I'm thinking about is in the blower speed control resistor assembly.

The problem is that the fan is blowing at high speed when the key is turned off.

If that is the problem, replace the speed control resistor. This assembly for the manual HVAC is around $20

I'm not gonna take the time to look it up (but you can search on here), if you remove one of the blower fuses, the fan will stop. I think it's fuses #35 (under the hood).
If you don't pull the fuse, or the battery terminal, you will kill the battery.
__________________
Ray
Reply With Quote Quick reply to this message
  #4  
Old 06-03-2009, 07:23 PM
the roadie's Avatar
the roadie the roadie is offline
No longer with us
 
2004 GMC Envoy SLT "Roadiemobile"
Extreme Offroad Pewter 4.2L I6 4X4
Join Date: Apr 2005
Posts: 26,181
They probably think it's a bad dash control module. Trailvoy knows better. It's a cheap item available in the aftermarket parts shops. No need to get it from the dealer at all.
Reply With Quote Quick reply to this message
  #5  
Old 06-04-2009, 01:47 AM
Super 88's Avatar
Super 88 Super 88 is offline
TrailVoy Alumni
 
2005 Chevy TrailBlazer LS EXT
Midnight Blue Metallic 4.2L I6 2WD
Join Date: Oct 2006
Location: North San Diego
Posts: 2,667
Quote:
Originally Posted by lifl2003 View Post
Hi all,

My 03 TB's a/c fan blows on high and will not turn off even when the power is turned off.
My EXT did that ONE time. I stopped at my friends house after a 6 hour drive. Turn the key off and the fan kept running. I was tired and at first thought maybe I hadn't turned the key all the way off or something. I tried several different things, nothing worked.

I finally tried restarting the vehicle letting it run for a few seconds and then turned the key off and then the fan turned off. I was worried that my battery might be dead the next day, but everything was back to normal.

That was about 2 years ago. Hasn't done it since. Talk about weird!
Reply With Quote Quick reply to this message
  #6  
Old 06-04-2009, 04:46 PM
RayVoy's Avatar
RayVoy RayVoy is offline
TrailVoy Guru
 
2009 Chevy Avalanche LTZ
Black 5.3L V8 4X4
Join Date: Jul 2006
Location: Atlantic Canada
Posts: 6,431
Super, in the manual HVAC speed control modules, there is a relay for the #5 speed. The relay operates in #5 and the closed contacts complete the circuit to the blower.
The relay requires the key "on" to operate, but the power for the fan (fuse #35) is a non-switched supply.
Relay contacts, sometimes arc and burn, causing a pit in the contact face. Sometimes the rough surface will freeze the contact and not release it, thus leaving the blower circuit switched on when the relay has released.
__________________
Ray
Reply With Quote Quick reply to this message
  #7  
Old 06-04-2009, 05:04 PM
bigcees's Avatar
bigcees bigcees is offline
Junior Member
 
2003 GMC Envoy SLT
Imperial Blue Metallic 4.2L I6 4X4
Join Date: May 2009
Location: woodstock ON
Posts: 12
definitely could be the resistor,Gm has always had a problem with these being susceptible to moisture. As you will see that the new one has been changed in design it shouldn't be that much and you can replace it yourself and spend that extra money on some new mods
good luck
Reply With Quote Quick reply to this message
  #8  
Old 06-05-2009, 12:43 AM
Super 88's Avatar
Super 88 Super 88 is offline
TrailVoy Alumni
 
2005 Chevy TrailBlazer LS EXT
Midnight Blue Metallic 4.2L I6 2WD
Join Date: Oct 2006
Location: North San Diego
Posts: 2,667
Quote:
Originally Posted by RayVoy View Post
Super, in the manual HVAC speed control modules, there is a relay for the #5 speed. The relay operates in #5 and the closed contacts complete the circuit to the blower.
The relay requires the key "on" to operate, but the power for the fan (fuse #35) is a non-switched supply.
Relay contacts, sometimes arc and burn, causing a pit in the contact face. Sometimes the rough surface will freeze the contact and not release it, thus leaving the blower circuit switched on when the relay has released.
Thanks for the info. I almost never use the 5 position. 4 is usually high enough for the front, and 1 or 2 for the rear. But that's interesting.
Like I said it hasn't done it since (knock on wood) But at least I know where to look if it does.
Reply With Quote Quick reply to this message
  #9  
Old 06-05-2009, 07:46 AM
lifl2003 lifl2003 is offline
Junior Member
 
2003 Chevy TrailBlazer LT EXT
Pewter Metallic 4.2L I6 4X4
Join Date: Jun 2009
Location: Long Island, NY
Posts: 7
Thanks guys

Is the "blower speed control resistor" the same as the "Speed control module" Does anyone know the part #?

Thanks again!!

Mike in NY
Reply With Quote Quick reply to this message
  #10  
Old 06-05-2009, 11:07 AM
cbwilsha cbwilsha is offline
Member
 
2003 GMC Envoy SLT
Pewter Metallic 4.2L I6 2WD
Join Date: Feb 2005
Location: Port Neches, Texas
Posts: 357
I'm assuming since you have the LT model that you have automatic a/c which means you need a new blower motor control module, part #89018778, which my dealer lists at $113.94. And it is no more than a 15 minute job to replace so whoever was quoting you $440 plus labor was really ready to rip you off in a major way.

Do a search above on "blower motor control module" and you will find instructions and pictures on the simple replacement procedure.

If you have manual a/c, you need the blower motor resistor. Do a search and you will find plenty of info on that option also. It is cheaper and just as easy to change.

C.B.
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum forums, you must first register.

Please enter your desired user name, your email address and other required details in the form below.
(Only letters, numbers, dashes and underscores are permitted for user names)
The user name that you choose is permanent and can never be changed.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

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

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

Forum Jump


» Sponsors

Advertising Info

All times are GMT -4. The time now is 02:39 AM.


Chevy TrailBlazer and GMC Envoy Enthusiasts - Copyright 2004 - 2009 All Rights Reserved.
All trademarks referenced herein are property of their respective owners.
RSS Feed