2006 Legacy 2006 heater works great on the drivers side, but only blows cold air on the passenger side. The same situation happens in the defrost mode (hot air out of the left vent, cold air out of the right vent). The quantity of air varies with the fan speed, but the air is dead cold on the passenger side.

I looked under the dash and behind the glove compartment and found nothing.

Dual climate control?

 

 

You have a bad electric motor in the HVAC somewhere.

 

nipper

I do not have dual control. I can only access the area through the glove compartment. Is there a way to get the the motor that may be bad? Is it in the center or the left side?

 

While I was looking for the problem I came across a white electrical connector that was disconnected. It is under the carpet, at the top edge of the passenger side floor mat. I reconnected it but it did not seem to do anything. I'm not sure what the electrical connector is for, or if was apart from the factory.

It may be a diagnostic plug. I'd leave it unplugged.

 

Most of the climate control system is in the center of the dash on cars these days. Usually requires removal of nearly the entire dash to gain access.

 

You still under warranty?

Make sure the airways arent clogged with anything. the way this system is made I can't imagine a scenraio like this unless it is parked in my driveway.

 

nipper

Make sure the airways arent clogged with anything. the way this system is made I can't imagine a scenraio like this unless it is parked in my driveway.

 

nipper

 

perfect!! check out your incar cabin filter!!

I have no cabin air filter (removed it a year ago).

I checked the cabin air filter housing and it was clean.

The car is parked inside except when parked in work parking lot.

 

Any suggestions on how to remove the center dash without damaging any of the plastic and vinyl?

The car has 92K miles, so I don't think they will fix this under warranty.

check out legacygt forums.

I have more information on this:

I removed the center counsel to get a better look at everything.

The motor that moves the damper between vent, heat, and defrost is working properly.

The recirculate/fresh air motor and damper are working properly.

The linkage for the cold to warm adjuster is working properly.

I could look into the air ducts to see the heater coil but I tried.

Having everything apart confirms the left duct is hot, the left-middle duct is warm, the right-middle duct is cool, and the right duct is cold.

I can't imagine the right side of the coil is blocked and the left side is open, but that is how it is acting.

Any suggestions as to how to get to the hot water coil to inspect it?

What boggles my mind is that the quantity of the air is the same all the way across the four ducts, but the air goes from warm on the left to dead cold on the right.

Thank you for any ideas that you have.

If you have heat and AC there is no reason to try to get to the heater core.

 

What happens if block the outlets that have air flowing in them?

 

Drop the blower motor and clean out the squirrel cage and the HVAC box.

 

nipper

This sounds like a common issue in some Ford and Lincoln cars with dual climate control systems. On those cars there is a valve that controls coolant flow to two separate heater cores. The valve nearly always fails one side fully open. So one core gets full flow of hot coolant, and the other is still regulated normally. Resulting in one side of the cabin getting hot air no matter what the setting, heat or AC, and the other side functions perfectly.

 

I don't know anything about the climate systems on newer Subarus, but I can see how this may be a possibility if your car has a similar setup.

 

Open the hood and try to find the hoses for the heater core. They're usually pretty easy to identify, but hard to follow because engineers always choose the most twisted and obstructed path they can find to route them.

It's not dual climate (I asked), as that would have been to easy.

 

 

nipper

Yes, but what's to stop them from using two separate cores even though it only really needs one?

Yes, but what's to stop them from using two separate cores even though it only really needs one?

 

Expense

Compliaction

Weight

Common sense

Space

 

 

It's just not done that way.

 

nipper

Sound like perfect examples of automotive engineering to me.

Sound like perfect examples of automotive engineering to me.

 

 

Thats what i am

 

 

Just for that your car gets four heater cores.

4 heater cores seems simple compared to SVX heater core replace as someone pictures here:lol: who ws the designer of this beast again roflmao

For a part that is not meant to be replaced often it seems fine to me. there are only so many ways to install things, but i will admit Jags do confound me. Anything you do on them starts with "step one remove engine", especially whenall you wanted to dowas repalce the glove box bulb.

 

nipper

I like my truck more and more when I see pictures like that.

 

Thats what i am

 

 

Just for that your car gets four heater cores.

Well sorry if I stepped on your feelings, but maybe we should get back on topic.

I like my truck more and more when I see pictures like that.

 

 

Well sorry if I stepped on your feelings, but maybe we should get back on topic.

 

 

Thats no fun

Thank you for your humorous back and forth.

I traced the hoses and there is only one supply hose and one return hose going through the firewall.

I tried taking off the blower motor yesterday but I couldn't get the top nut free. As I was struggling with this I noticed the AC coil would get the air first, the heater coil would get the air second. So if somehow a leaf made it though the blower, it would have gotten caught on the AC evaporator before it got caught on the heater coil. Once I realized that I decided not to remove the blower (upper nut pain in the a** anyway!)

Inside the ductwork, on the damper that moves when the cold to hot knob is turned, is is possible that one side broke free from the shaft and is not turning?

I'm thinking about going to a scrap yard under the guise of getting a heater coil to take everything apart to see how they assembled things at the factory.

Does anyone know if drawings showing the assembly are on line?

Or perhaps even a repair manual?

is it possible its a single heater core, but with 2 valves. reason being, they did make a dual climate control model hvac system, and that would probably have 2 valves, one for each side in the passenger compartment. Now, on a non dual climate control model, maybe it still has 2 valves but they operate in unison, and maybe that 2nd valve is not working??????

maybe your lever, rod, acuator came loose from the one valve, or maybe the one valve is stuck. I do not even know if there are 2 valves, but could very well be.

is it possible its a single heater core, but with 2 valves. reason being, they did make a dual climate control model hvac system, and that would probably have 2 valves, one for each side in the passenger compartment. Now, on a non dual climate control model, maybe it still has 2 valves but they operate in unison, and maybe that 2nd valve is not working??????

maybe your lever, rod, acuator came loose from the one valve, or maybe the one valve is stuck. I do not even know if there are 2 valves, but could very well be.

 

 

Except he said he does not have dual climate control.

 

Also they use one heater core and one ac evap for dual climate control. they just add in additional doors and motors to make it work.

I use Bar's Leak and the Subaru conditioner ("blue goo") in the antifreeze. What do you think about the possibility that the Bar's Leak has plugged the end of the coil. That would be the passenger end of the coil (where the flow would be the lowest)?

I'm thinking about doing a super flush and seeing if it helps any.