. . . it only blows at the coldest setting no matter where i put the dial from blue to red . . . Should I bother flushing the heater core . . . When changing the temp control knob to red from blue I hear nothing behind the dash.

There's a cable between the temperature control (at the back) and the lever that controls a flap inside the heater; the flap varies the amount of air going through the heater core, and thereby the temperature of the air out of the vents. It's a coaxial, or "bicycle" type of cable, with an outer casing held in position and a single wire that moves inside. It's possible that the casing or inner wire aren't fastened properly. Usually, when moving the temperature control, with the engine off (i.e, quiet), it should be possible to hear the mechanism working.

 

explained that very well thank you I now know what to really look for. Hard to access this cable? Is the flap that you speak of the white plastic on the passenger side I have seen? I also forgot I had a shop put in a new head unit so they may have also forgot to put it back on if they were near it.

I did go out and listen with it off and hear not a single thing and its very quiet where I live. Ill report back when i make any progress on diagnosing gonna need a day off to pull trim pieces off lol. cheers.

 

Good video, I think.

When the temp control is turned, we see the cable moving the white lever A, and pin at B moves with it. However, the pin at B doesn't seem to be connected to anything else. Usually a pin like that engages a cam follower. This is part C:

In the video, when B moves all the way to the left, we can see the upper end of C (at D) move slightly.

I suspect that the pin at B is supposed to be in the slot in C, so that as the manual temp control is turned, and lever A is moved, the pin slides along in the slot, turning C. Lever C is probably connected (at its right side end in this photo) to the air blend door inside the heater box. Perhaps the pin at B has somehow been pulled out of the slot, or, lever C is broken so that the pin isn't held in the slot.

The two parts can be seen in the diagram at: HEATER SYSTEM. HEATER UNIT & COOLING UNIT.. 2006 Subaru Outback 2.5L 4AT Base | Subaru Parts Online

 

Good video, I think.

View attachment 502574

When the temp control is turned, we see the cable moving the white lever A, and pin at B moves with it. However, the pin at B doesn't seem to be connected to anything else. Usually a pin like that engages a cam follower. This is part C:

View attachment 502573

In the video, when B moves all the way to the left, we can see the upper end of C (at D) move slightly.

I suspect that the pin at B is supposed to be in the slot in C, so that as the manual temp control is turned, and lever A is moved, the pin slides along in the slot, turning C. Lever C is probably connected (at its right side end in this photo) to the air blend door inside the heater box. Perhaps the pin at B has somehow been pulled out of the slot, or, lever C is broken so that the pin isn't held in the slot.

The two parts can be seen in the diagram at: HEATER SYSTEM. HEATER UNIT & COOLING UNIT.. 2006 Subaru Outback 2.5L 4AT Base | Subaru Parts Online

Wow I could not see part D last night with my eyes haha. This gives me some hope I appreciate the annotating on my own personal video. This helps heaps and I think ill try and contort my big ole hand up there and see if itll stay in that slot by hand or not I have had the head unit replaced and the airbag recall has been done so good chance it just lazely was never put back.

Worst case ill start firing out DIY's. May have to wait til after aisin belt kit gets put in. Regardless been interesting seeing how the dash hides things and how mechanical can just be pulled out fo function.

 

This helped me too...

A little background... I had intermittent A/C issues that ended up being a switch in the control unit that isn't replaceable. So for $29 I got a junkyard control unit and replaced that, but had a time getting that actuator cable connected up high under gas pedal. Once I did get it connected I had great A/C but no heat. Your video and Plain OM's posts helped me too.
I was able to contort myself and get one hand up there to move the cam follower lever and my long, bent at end needle nose pliers to lever the pin back in. Whew talk about claustrophobia under there, but glad to have finally gotten it fixed-for free!
Thanks to both of you!

 

@SubieSwede

Does the knob turn through the full range?

If the cable outer case is secured at both ends, and the inner wire is securely attached to the lever up on the side of the heater box (post #9), and to the control in the heater control panel, then perhaps the gearing on the latter is damaged.

I believe this photo is representative of the temperature control. The knob turns the pinion gear, which acts on the rotation gear. The latter includes the lever to which the cable is attached. If the knob is rotating fully, but the cable center wire isn't moving, then the problem might be in the pinion or rotation gear. It should be possible to view the action of the rotation gear when the knob is turned, perhaps using an inspection mirror.)

 

Thank you for your timely and helpful reply, plain OM.

The cable’s outer case…I know it is attached 100% at the end I described in my previous post but where and how does it attach closer to the heat control panel?

pretty sure the gears are fine, but thank you for the possible failure point.

Best!

 

. . . where and how does it attach closer to the heat control panel?

I believe the cable comes into the control from underneath. The end of the outer housing will be held in the curved tabs seen in the "underneath" image, while the center wire hook continues toward the left, passing on the top side where it engages with the rotation gear lever.

 

You are probably on to something here. In my case I’m not routing the “casing” through that notch. Will try to make that happen and report back.

 

I would think a small amount of a multipurpose synthetic grease would be adequate.