Hello,

I've searched many places but i cannot seem to find the answer to my issue. I have a 1999 Chrysler Concorde that has an ATC Module. The other day it began to display two dashed lines in place of the temperature and would automatically turn on the defrost mode. If i turn off the air it turns back on almost immediately and back to the defrost setting. The same thing happens when I try to switch to a different mode. The temperature controls, as well as the fan speed control, do not respond or have any effect on the defrost. I was wondering if anyone else has had this issue and how they corrected it. I can replace the ATC Module if needed but I want to make sure that it's the issue before doing so. I've attached a picture of what my display is showing and here is a link to a video of the issue as well: https://photos.app.goo.gl/PfmY01Te0l57g59d2+

Thanks for your help

 

Correction, this is the link to the video: https://photos.app.goo.gl/iNNKk3rIE1ptxp343

 

I have the very similar ATC in my 04 T&C, there is a test/calibration test YOU can do using specific control buttons on the HVAC control panel, it will give codes of what problems it finds on the control panel and if passes will calibrate movement of the various doors. Sorry but can't remember the test sequence,to post it here for you. Google search Chrysler auto temp control test or reset may help you out.
GoodLuck, and post back if you find anything.

 

Yeah the 3 button test was one of the first things I did, but no codes will display. The temperature lines stay dashed like in the picture, even when it runs the test. That's what is leading me to believe the ATC needs replacing itself.

 

Solder joints notorious for failing on these controls.
Repair: https://300mclub.org/forums/viewtopi...+repair+solder

 

Thanks! Unfortunately, the website you linked is saying I'm not authorized to view the forum. Even after I made an account. Any way you'd be able to take a screenshot or copy the repair to here?

 

That link was in the "Members Only" section.
This one is in the General Forum. Open up unit and resolder the 3 blue resisters. Poor/cracked solder joints may not be visible but are a common cause.
https://300mclub.org/forums/viewtopi...lit=ATC+repair