1st time ac problems

[misha]

Before i blame ecc control unit for failure i just need to know are ecc units interchangable for all 850s or there is a difference between years?
No flashing ac/rec lights but somehow i have a feeling that after around 30min air is not comming from the wents like it should.
Blower works on high speed and everything is fine for a while but after around 30min very little air comming out from the vents even if i hear that blower works at high speed.

Problem appeared after ac system is being checked and serviced.

When car sits overnight and everything is cooled down ac works perfectly...but after a while it starts to going on my nerves.

Never,ever had problems with ac since i have the car,except regular service around 3 years interval.
I suspect ecc or worn/slipping clutch on the compressor.

[abscate]

If the air flow changes, Misha, something is up with the air dampers. It could be the ECC control unit but more likely a damper motor is not working right

[misha]

Air dampers which lets air inside the cabin?
There are two of them right?
I think that they can't be both bad out of a sudden.
Also....all working fine for around 30min or so and ac blows ice cold...then something start acting up.
Something which controls them is making problem...in this case...it's ECC.
I suspect that it's rec motor.
I'll make flash code reader to see if ECC is complaining about something...but lights are not flashing.So i presume that there are no faults.
Is there a possibility that clutch is slipping when it becomes hot under the hood?

[Clemens]

as far as I know the ECC units are interchangeable regardless of the model year. at least in my case my 95 received a different year ECC and everything worked nicely again

[misha]

I thought about ECC units from up to '95 year cars because i can pull it out from '95.
If i could find one from '96 & '97 i know that they would work...no doubt about that.

What was the problem with yours ECC,Clemens?

[abscate]

The clutch slipping when hot is common, and is covered under the “ bread clip fix” here a lot. You can measure the clearance when cold to see if it’s in spec. I’ll look for threads with pictures

[misha]

Is damper motor for air flaps accessible from under the steering wheel?
I would like to remove it and test it.
From what i read it is controled by ECC from various inputs from ac sensors.
I'm not removing the whole dash for this.

[Clemens]

What was the problem with yours ECC,Clemens?

out of the blue, my fans would start ramping up and down, the temperature was very inconsistent and i had a bunch of codes that I can't remember.

[misha]

Strange that ac & rec lights are not flashing on start-up so i presume that there are no codes stored in ECC.
It starts acting up when things are warmed up.
When it sits overnight and everything is cooled down,it works normally.
I also figured out that it works perfectly in the night when there is no additional heat from direct sunlight.
Could be that solar sensor in front of windshield is at fault...or ECC is sending wrong information to damper motors.

[abscate]

Clean the fan that pulls interior air in and feeds interior temp to the ECC control unit