Air only blows on windshield and dash vents

CEBirnley · Post by **CEBirnley** » 29 Nov 2020, 11:33

1998 V70 fwd, fuel injected, no turbo.

I am trying to diagnose an issue with the a/c and heat only blowing through the dash vents and windshield vents. Regardless of where I have the selector set, the air continues to blow through the windshield and dash vents only. I am not hearing the blending doors operating. I am unsure if the issue is with the rotating switch or the doors themselves.

Please advise on what links I should be reviewing on this site to determine the scope and remedy of this issue. Thank you.

Post by **FLXC90** » 29 Nov 2020, 19:35

Do you have Manual or Electronic Climate Control (knobs with Numerals or not) This will determine what type of troubleshooting to perform.

CEBirnley · Post by **CEBirnley** » 29 Nov 2020, 20:10

No numerals. Just images of where the air will be blowing when the dial is placed on that selection.

Post by **abscate** » 01 Dec 2020, 07:07

The base model US as two options for Climate control

Manual Climate Control (MCC)
Electronic Climate Control (ECC)

ECC is often loosely used to describe the controller unit in the dash of the electronic system too

If you have MCC you just have red blue stripes for temperature select indication. With this system the fault is usually the cables have come loose

ECC will have numbers in F for US and in C for third world countries that use the antiquated metric system

With this system it’s usually a controller error, but the actuator can also go bad

Post by **abscate** » 01 Dec 2020, 07:08

Ah, MCC it is

I link you to the disassembly thread shortly

Ding!

https://www.matthewsvolvosite.com/forum ... 57#p504757

I believe MCC temperature operation is cable/manual controlled while air flow selection is electronically actuated, so you might be into new territory here. I’ll have to search for MCC air actuation threads, nothing recent

CEBirnley · Post by **CEBirnley** » 01 Dec 2020, 20:05

Thank you Empty Nester for the assistance. My baby only has 160k on her, yet she’s starting to burn oil, the EVAP system appears to be having issues AGAIN (just replaced it 3 years ago) and now the issue with the vent doors not directing the air properly. She’s been a solid car until now...

Post by **abscate** » 02 Dec 2020, 04:47

I think I have a spare MCC actuator from Clark if troubleshooting comes to that. These things rarely break