My 2012 caravan had the battery disconnected for bumper hitch wiring, now rear window defroster blinks and for 30 seconds I have no hvac power, any ideas on how to reset the door recalibration which activates the blinking when any door is opened.

HELP dealer is clueless

 

Hello
I have the same problem and i dont know what to do did you finally Found the problem

 

Hi Donald, We certainly understand why this may be concerning. We kindly recommend having your dealer inspect this concern for you as they are in the best position to assist. If you do work with your dealer, we would be more than happy to provide you with additional support.
Rob
DodgeCares

 

The HVAC system has an automatic re-calibration test built in anytime you disconnect the battery it will re-calibrate the system blend doors if the re-calibration test should fail the rear window defrost will blink and will shut down the power. You need to get someone with a scanner to determine which blend door has failed the test which is causing the issue and if a re-calibration can fix it.

 

I have a 2014 Ram 3500 Limited and I had this happen at the same time my brothers '16 Charger had the same problem.



In my truck the mirror defrost button (i mistakenly thought this was my rear defrost button which my truck doesn't have) started blinking and didn't stop. While this was happening I couldn't change anything on my HVAC except fan speed. I couldn't even turn it off.



I took the truck to the dealership & the only remedy they could offer was flashing the ECM. I agreed & $115 dollars later it was still blinking. They then suggested that they could pull the whole dash & check the blend & recirc doors. I declined.



I pulled fuses, unhooked the battery - no fix. Same for my brother & his Challenger.



I finally changed the HVAC Control Module. OEM was $100 & the only tool required was a phillips screwdriver. The process took 10 minutes start to finish. I started the truck and the light started blinking but I held my breath. After the truck went through all its self checks, the light went off & all my controls worked. J did the same on his Challenger and his went back to normal as well. The light is the computer's way of telling you that self diagnosis has failed.



Apparently the module's memory can fill up and cause it to fail. Sometimes pulling the battery will cause the same thing.

 

My blinking rear defrost kept blinking after I replaced the blend door with a cheaper aftermarket version. I decided to put a genuine Mopar blend door in and the blinking stopped. When the aftermarket door was in, the van tried to calibrate it every time I turned the key. This went on for a coupe months. I believe this also helped drain the battery because just opening the doors made the blinking occur. So, after replacing it with a genuine part, the blinking stopped after just one key turn.