Is it possible that the A/C control in the dash (auto climate) won´t activate the compressor due to low ambient temperatures.
I hit the button and it only blinks 3 times then stays off. Same with the two buttons underneath the blower control.
Blower **** is turned to 12 o clock, temp same and duct **** is set to windscreen.

 

Anyone?

 

Quite normal . The AC-Compressor will not work below 5 degrees Celsius . Greetings from europe...

 

But how does it dehumidify the cabin air if it wont engage? In my other car it is possible to run the compressor at whatever ambient temparature.

 

Hello,

I live in France and I'm spending my first winter with my 2001 Blazer. Getting rid of all the humidity in the cabine without the AC is nearly impossible. I have no coolant leak as my level in the tank is perfect in the last 5000 km.
How can I force the AC on ??? This system "automatic controle" is a big piece of S....t ! Sorry to say but not having controle of the system is a bit frustrating. Can someone help me ??

1/ Who to override the A/C ? How can I put in ON and not have the 3 blinks and then nothing ?
2/ do you also have misting problems ? how do you handle it ? What mode is the most efficient ? Do you take air from out side ? Inside ? etc...

I was on the highway going to the ski ressort and the car started misting up after 3hours drive and then it was finished ! Could not do anything except wipe the windscreen with a t-shirt ;-) I had to put an electrical heater in the car during 1 hour to dry up the cabine during the evening !

I really need help as this situation is quit dangerous.

Many thanks in advance and Merry X-mas to all !! ;-)

 

The A/C will be used whenever the system is put into defrost. The light will not be on.

 

Does not seem to happen !


To be more general : No sign of coolant in the cabine (Passenger footwell clear).
Heating works great ! Got the coolant changed at dealer 3 month ago, engin and cabine heater flushed then.
Everything is fine except the fact that I have mist on windows inside the car as soon as the heating starts.
If I defrost I have a few patchs of clear vision on the windscreen but I can not get the entire windscreen to be clear. The rest of the car stays misted.
If I go back to auto mode, windscreen starts misting again after a while.

Where can the humidity come from ? How can I force the AC on ?

 

You cannot force the A/C to be on aside from jumping the compressor clutch which would defeat any of the safety features in the system and may result in damage. Even with the A/C compressor jumper'ed, it would take A LONG time to dry out the interior. It isn't worth the effort in my opinion.

If you have leaking door seals and/or leaking weather deflectors behind the door panels, moisture can come in from the outside. Another possible source of moisture is a blocked drain in the hvac housing. The drain is directly above the passenger side frame rail at the firewall under the hood. If it cannot drain, the moisture cannot escape.

Also, if you get into your vehicle with lots of snow on your shoes, it will saturate the carpet and hang around for a LONG time in the winter. This is especially true if you have carpeted floor mats. I prefer plastic floor mats for the winter that have channels in them to capture the snow/water/slush junk and can be dumped periodically. This will dramatically cut down on the moisture in the cabin.

To dry out the interior, you could try some desiccant bags or put a dehumidifier in there over night. You could also throw some newspaper down in the foot wells to pull moisture out of the carpet.

To check whether the A/C is engaging as it should in defrost mode, set the hvac to defrost and check the compressor to see if it is engaging. It will not run continuously when in defrost.

 

Thank you for your complet answer.
I have to acces the drain to check if it is clear or not.
I saw in an other thread that it was easier to access it by the wheel arch ? is that correct ?
I took a look under the HVAC and there is a little heat shield. Is that the correct location ?
Could you take me through the proces ? Or maybe show me a picture ?
Should I take the wheel off ? etc...

Many thanks

 

I do not have a picture. When I cleaned the drain on my old '00 Bravada, I already had the inner wheel well out on the passenger side. That was a lot of work, but made getting at things easier. You can't really see the drain hole from under the truck looking up at the frame rail, but a small mechanics mirror will help bring it into view. It will be on the lowest point of the HVAC housing at the firewall. It is easiest to clean using compressed air.