Ventilation bad smell definitive solution - Jeep Garage - Jeep Forum

Go Back   Jeep Garage - Jeep Forum > Jeep Platform Discussion > Export & Diesel Powered Jeep Models

Thread Tools Display Modes
Old 12-30-2016, 07:41 AM
New Member
Join Date: Sep 2013
Posts: 2
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
lelez is on a distinguished road
Cool Ventilation bad smell definitive solution

I have read plenty of times in many forums about the bad smell coming from the ventilation of our WK2s,
it's really annoying and it often makes my 2 years old child cough.
As I am an electronic designer of HVAC controller (for buildings), I am headed to modify the GC HVAC controller to definitely solve this issue and I will be happy to share the solution to help other owners.
I believe chemical treatments are not a solution since they will be effective for days rather than weeks, totally unacceptable.
I have been driving my 2011 diesel for three years and I can say the issue appears only during winter and not in summer.
My opinion about the cause is that during the cold season the AC pump is turned on at some time even if there is no need to cool down the cabin, this happens even if the AC button is OFF (AC button LED off).
I think the HVAC controller does some de-umidification cycles periodically or something similar which makes the AC pump turn on for a few minutes and then off.
In every car I owned, when I used to turn off the AC, I used to get that bad smell, so my abit is, in summer the AC always on and in winter AC always off. Except some rare situations this always worked fine for me.
Now the problem is that in the GC it is impossible to keep the AC always off, as the AC button in not a true on/off switch and indeed I don't understand what is it meant for since the controller drives the AC pump regardless what I set with the AC button.
I need help to locate the PWM driving signal wire of the AC pump, if it is possible to find it in the HVAC controller that would be great.
I asked my Jeep dealer here in Italy for a wiring diagram but I got only an unuseful screen print.
I hope somebody can help on this since I don't want/have no time to dismount half of my GC to see where the wires go.

Reply With Quote
Sponsored Links
Old 01-08-2017, 04:30 PM
New Member
Join Date: Sep 2013
Posts: 2
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
lelez is on a distinguished road
Re: Ventilation bad smell definitive solution

Dismounted my GC and found out that the AC pump is not PWM, it's just ON/OFF, the electromagnetic clutch type.
When I start the engine the AC pump is turned on immediately, and it stays on even if it's cold and I ask for heating in the cabin.
On the HVAC panel there is no wire that seems to operate the AC pump, if I turn off the HVAC panel, the AC pump is turned off after 3 seconds.
I think the HVAC panel send somebody else the AC pump request via CAN bus.
I disconnected the AC pump connector and the bad smell is gone.
I am happy now I can breathe while driving .
The AC pump connector is hard to reach and operate, and I don't like to have it exposed to dirt and oxidation, so I would need to know if there is a relay or fuse I can easily remove to stop the AC pump.
Reply With Quote

Thread Tools
Display Modes

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 Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Bad smell through heater tonyee New Members - Welcome! 5 12-29-2016 01:30 PM
secure ventilation for dog in Unlimited hardtop? travelhawk Wrangler-YJ, TJ & JK 6 09-16-2014 04:32 PM
Need some definitive tire and wheel help . . . Fght On Grand Cherokee SRT - WK2 11 09-12-2013 06:28 PM
Recirculation Ventilation Control Swampy Export Grand Cherokee 2011+ 10 08-20-2012 10:00 PM
Definitive answer on the Koni FSD? mcalc55 Suspension/Brakes/Wheels/Tires 6 03-23-2012 02:48 PM

» Premium Vendor Showcase
Powered by vBadvanced CMPS v3.2.3

All times are GMT -5. The time now is 04:52 AM.

Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Copyright 2012 - JeepGarage.Org
The Jeep Grand Cherokee Owners Community is in no way associated with or endorsed by FCA US LLC. Chrysler, Dodge, Jeep, Ram, Mopar and SRT are registered trademarks of FCA US LLC.