2001 v70 Fan Blows Air, But Not Hot On Passenger Side

Post by **packetfire** » 09 Dec 2014, 14:30

My heat works fine, on the driver's side only. Passenger side, air does blow out all vents, but it is consistently cool, not at all hot. VIDA gives me no codes about any of this.

But it seems clear that the barn doors are NOT diverting air for the passenger side over the heater core, but are doing so for the driver's side.

I have this diagram, perhaps there is a more detailed one somewhere in VIDA:
https://www.matthewsvolvosite.com/forums ... =16370&t=1

I removed the glovebox and the panels in the passenger footwell, and removed the servo that is directly below the large white wheel, the one flagged with the grey square in the diagram image, the middle of the 3 at right. When I turned the temperature control for the passenger side low and high, it moved back and forth, and I could manually turn the plug into which the rotating spindle fits, but I could not see to verify that a barn door was actually opening and/or closing.

Any clues that anyone could offer to how to see the barn-doors work would be a big help, as would a definition of which servo does what of the 3 on the passenger side.

Thanks!

Post by **abscate** » 09 Dec 2014, 16:19

Do you have manual or electronic climate control?

There are several threads on this problem which I will seek

Post by **packetfire** » 09 Dec 2014, 17:13

The 2001 v70 was the first year of the "P2" chassis, with electronic, dual-zone climate control, so driver and passenger each have a temperature knob on the center console. Further, there is a single temperature sensor, behind a small grille built into the Climate module in the center console.

Post by **packetfire** » 11 Dec 2014, 21:05

An update after further poking into the situation:

1) The lowest servo on passenger side of center console closest to the rear of the car is the correct servo. Turning the passenger temp knob warmer makes the servo rotate its rod toward the rear of the car, turning the passenger temp knob colder, makes the servo turn its rod towards the front of the car.

2) Removing the servo motor and turning the plastic socket into which the rod fits with a 3/8ths socket wrench extender bar results in a satisfying audible thump when the door hits the limits of its travel.

But while the fan blows air out of the passenger-side center console, dash-by-door, foot, and windshield defroster vents in accordance with which selections one makes on the climate control unit, this air is never warm, never hot. Driver's side is hot, as it should be. In all of these tests, A/C is disabled, so the cool/cold air is not being chilled by the A/C unit. Air volumes and velocities coming out of the vents seem equal between driver's side and passenger side, holding a hand in front of each to guesstimate volume and velocity.

So, I am completely stumped here, and I am wondering what I can do, short of pulling the entire dash and pulling the ductwork box apart to watch the doors move with my own eyes.

Any clues, anyone?

draser · Post by **draser** » 12 Dec 2014, 07:03

Any way you could look at driver side range of motion cold to hot to compare to passenger's? Cabin filter clean?

Post by **DGM** » 12 Dec 2014, 07:27

packetfire wrote: Any clues, anyone?

The cabin temperature sensor can get dirty on these models. The little fan inside gets stuck by lint accumulation. Be careful of the pin head device behind the grill it is very fragile. In severe case the fan housing must be removed, disassembled and cleaned.

https://www.matthewsvolvosite.com/forums ... =9&t=48562

See the comments of "oilburner" in the following post;

http://www.volvoforums.org.uk/archive/i ... 63988.html

Here is how to remove the climate control unit. It is important to disconnect the battery otherwise you may trigger error codes;

Post by **packetfire** » 13 Jul 2015, 12:02

Never found a solution on this... is there any way to see the barn doors open and close that involves less work than pulling the entire dashboard? From a servo point of view, all seems fine, but the passenger side gets no heat. The passenger side DOES get fine A/C which stumps me. The sensor in the CCU is clean, and the fan seems to turn easily when I blow on it with canned air, so it is not gummed up.

Post by **oragex** » 13 Jul 2015, 16:08

I've noticed that that from drivers side, if you remove the plastic on the left side of the center tunnel, then the trim above driver's legs (two torx screws), you can get a view at some of the mechanism that opens the a/c duct.

Post by **Vovo_merz** » 13 Jul 2015, 19:15

Didn't read all the responses you got and sorry if someone already suggested this but it sounds like you need the climate control system calibrated anyone with vida dice or dealer can do it, had exactly the same problem like yours only on A/C one side didn't blow cold but heat worked on both sides, and works like a charm after calibration

Post by **abscate** » 14 Jul 2015, 04:33

You could drill a hole into the climate system, then plug it when done with a plastic plug.

Inspect the barn doors with a fiber camera scope. I'm not sure you can fix anything this way but you could at least diagnose.

Alldata reports 9.8 hours for an evaporator core R/R so it's a weekend job to get the climate system out and sorted.