My rear-window defroster button light is continuously blinking on and off. Also, the AC switch does not work. The only thing that works in my heating is my Front Defrosters... So I know the blower motor is good.. No matter what position I put the **** in it blows threw the defrost.

Anyone have an idea what's causing the rear defroster button to blink on and off, and making my AC switch inoperative?

Thank You!

 

I'm having the same problem. Have you found a solution?

 

My rear-window defroster button light is continuously blinking on and off. Also, the AC switch does not work. The only thing that works in my heating is my Front Defrosters... So I know the blower motor is good.. No matter what position I put the **** in it blows threw the defrost.

Anyone have an idea what's causing the rear defroster button to blink on and off, and making my AC switch inoperative?

Thank You!

 

You check all the fuses?

 

All fuses check OK !!!
I had it to my dealer and they "recharged" the AC, and were lost after that. They said that it might be the "mixer box" and said that it might be $1,300.00 if they had to replace it.

Here is what I have checked and done:

When I power the ignition (without the engine running) I can hear all the speeds on the fan running, I can hear the doors moving with each different position (floor, defrost, etc) the temp slides also move the accuator for both driver and passenger. When I push the rear defroster (blinking button) I hear a relay snaping in the engine compartment. When I push the AC button.....nothing.

With the engine running, I can push the AC button and the compressor engages and stays engaged(but no light on dash button - - that usuallycomes on when the air is on. The extra aux. fan at the radiator clicks on and the aluminum piping gets all frosty and very cold to the touch.

I don't think it's the switch, bu the way, NO COLD AIR AT ALL - NOT EVEN COOL. Just hot from the engine and if I slide the temp gages up it gets hotter.

Please help, Phammel

 

A blinking rear defrost light indicates a malfunction of your climate control unit. If you are lucky, you can get the unit reset at the dealer for about $50 to get the AC back but the light may still blink. The light is the EBL status indicator. It can flash at two different rates, twice per second (fast rate) when the control is indicating that the HVAC Door Recal needs to be run, and once every two seconds (slow rate) when the HVAC Door Recal is in progress. When the indicator is flashing, the AC status indicator will not function, however the AC switch will contine to function normally. (info via DurangoClub.com)

At a minimum, you now know what is wrong and can get it addressed according without getting screwed over by un-needy repair expenses.

HTH,

IndyDurango

 

I'm having the same problem with my 2001. Mine comes with some history though. My A/C compressor along with my idle speed censor went out about 5 weeks ago...$1500 later I have coldA/C and a smooth idle.2 weeks later my PCM went out...After 2 attempts with a used one I ended up having the dealer replace it with a new one for $630. When I went to pick it up I noticed the A/C light wouldn't come on and the defrost light was blinking. I made a U-Turn and brought it straight back. After another 1/2 day without my ride they tell me the A/C Control Head was bad and I needed a new one for the tune of another $350!! I didn't buy their story that it had nothing to do with the PCM since it doesn't share any circuits with it (BULL!). So I left the dealer telling them I'll replace it myself before I gave them any more money. I picked up a used A/C Control Head for $90 hooked it up and...low and behold it did the same freakin thing! As you can imagine I was pretty ticked when I brought it back to the same dealer ( I know, I know, I figured I would give them one more chance to redeem themselves) Well they didn't. They worked on it for another 3 hours and told me that they were able to recalibrate the new control head but afterwards it saw an error with the mixing door position and started flashing the code. At this point I'm pretty disgusted and pretty sure that there was nothing wrong with the control head to begin with. So after all that rambling...where can I find this mixing door? I got the feeling it was locatedin the rear of the vehicle. I know there is no direct cable to it because the control head is all electronic. Please tell me someone has figured this HEADACHE out!! Help!

 

AGAIN, a blinking rear defrost light indicates a malfunction of your climate control unit. There is no need for the stealer/dealer to spend 3 hours 'trouble shooting' the issue. Have them sepcifically repair and review the climate control unit.

IndyDurango

 

They did all that. They said theyreset and recalibratedboth the new one and the one I bought to replace it, but it is still showing the code for the mixing door. I believe its the fast blinking rate, so what exactly needs to be done to fix it? Do I need to physically get to the door and make sure its operating?

 

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.