1st time ac problems

[scot850]

Misha, if you have not already done so, remove and clean the 2 cabin temperature sensors. There is one hidden about each grab handle about the front driver and passenger seats above the doors. You have to remove the grab handle and some of the door trim to get to them but fairly simple. Carefully clean with IPA (medical alcohol) using a cotton bud (used for cleaning carp out of your ears!). You will find a whole bunch of dirt and stuff that block the small fans in the units pulling cabin air over the temp sensor.

If you have not already done this then do it anyway as when jammed they cannot sense the cabin temp correctly and it plays crazy with your ECC system.

Neil.

[misha]

I cleaned them 2 years ago when i had flashing ac & rec lights,no problem since then.

Blower speed corresponds when i move temp selectors high or low but amount of air which gets out from the vents is pretty low.

But the thing is that....when it starts acting up i hear the blower working on high speed but very little air is comming out from ALL vents...something like vents openings are almost closed but they are always fully opened.

When it sits overnight and everything is cooled down,cold air is blowing like crazy from vents like it should.

As far as i could investigate,it might be the problem with damper motor for ventilation or ECC is sending the wrong signal to the motor.

I will also check outside temperature sensor....it might be out of range...who knows.

I hate those intermittent problems.

[greg850r]

I would swap another ECC because it's quick and easy. It could be the problem but if nothing else would rule it out.

The damper motors are hard to access. This illustration shows where they are. I found it in this thread viewtopic.php?t=50525&p=251432 He did it without removing the dash. If both sides are the same when the airflow gets restricted it would seem to rule out the motors that only control one side.

Screen Shot 2019-08-31 at 8.03.33 AM.png (52.8 KiB) Viewed 428 times

I don't think I would change them without removing the dash and as previously stated the best writeup is here: http://www.woodjoiner.com/volvo/VolvoEvapReplace.pdf
Here are pics of 2 of them to give you an idea.
I borrowed the pic of the left upper damper motor from this writeup. The pic of the passenger one is mine.

L damper.png (382.72 KiB) Viewed 428 times

R damper.png (238.52 KiB) Viewed 428 times

[misha]

Which one on the driver's side controls main ventilation(the air which should blow out from the vents)upper or lower one?
It should be upper one...i guess.

Checked ECC,no codes stored and no flashing ac & rec lights.

Cabin temp sensors checked...all is ok.
Little fans are spinning initially with key in pos.I,then stop and they activate again as soon as i turn on the fan via slider switch.
Air distribution works in all directions,temp dials works...rec button works....ac button works.

Last two days ac works perfectly,but all trips are up to 30min only.

[greg850r]

Which one on the driver's side controls main ventilation(the air which should blow out from the vents)upper or lower one?
It should be upper one...i guess.

I think you are correct but cannot verify as I pulled all the motors and got rid of the air duct box 2 weeks ago.

[misha]

Ac blows ice cold from my last post even on 40+ minutes long trips,so i will put this on hold for a while untill i have some time to check damper motors for air ventilation.
Still no ac/rec flashing lights from ECC and no codes stored which is strange.
I really hate this intermittent problems.
Something is happening when heat builds up,but i'll nail this down.

[wizechatmgr]

If you get enough heat built up, there was (or may still be) a thermal switch on the side of the compressor near where the clutch's electrical plugs in that can flake out.

[misha]

The little square black thing?
I saw those connectors....maybe they needs to be inspected and cleaned.