New and have a question
 

I have a 2005 XC70 that I love but in the summer it has the air conditioning issue. I am thinking it is the thermal by pass but my car does something that I haven't found in other discussions of this topic. Thought I should ask about it before I do the "wire around" solution. When the outside temp gets above 90 degrees and you turn on the air conditioner it runs fine for a couple minutes and then I hear a sound like a vent door is closing in the system and air flow drops dramatically. Then sometimes after and hour or so it suddenly opens and the air is now coming through the vents again and things cool right down. Is this still related to the "by pass cut off" or a different issue.

Thanks in advance for any help and glad I found the site.

What you are describing sounds like the recirculation door closing to draw interior air back through the system. I'm wondering if the flap to close the outside air is closing but the interior flap is not?

Try overriding the recirculation button when it does this and see if the air flow returns.

I think you could very well be on to something - I have tried all the selections on the control panel so not sure how to over ride the recirculation button. Is there anyway to get to the door or determine if it is open or closed. Again, thanks.

HI i have a Volvo S40 and my radio is locked. Dose anyone know how i can get the code to unlock the radio please?

There is a button with a circle that has a circle icon. In this link, it is the button on the upper left.

https://www.ebay.com/itm/VOLVO-XC70-...8AAOSwXJNZb7de

When you sense diminished airflow, see if the light is on for the button in the upper left. If so, push the button once and the light will go out. See if the airflow improves.

If that solves your airflow problem, then the problem that I'm describing is what you have.

Memo to Kiwiboy773: Please start a new thread when not contributing to the topic at hand. Button is located upper left under the main nav bar. Suggestion: Use the search tool for existing threads which talk to finding radio codes.

Comment to Purplesage - if you feel inclined to open up the console you may be able to see if the actuator arm from the motor to the door has disconnected somehow.

Sounds like opening the console could be a bit of a reach but I may end up trying it just because I live in Idaho and have hot summers so it means I am driving my truck way more than I want to (it has a good working air conditioner). Is there a thread I should look into or is this new territory.

most Volvos have a similar design - I'd probably start by looking on Youtube for a vid on replacing the heater core for similar year/models as a way of seeing how to open up the center console

Well after screwing around with this for a couple weeks I am back to thinking I should wire around the thermal by pass. I get restricted air flow when ever the temp is above 80 degrees - as soon as it drops below 80 the air conditioner is suddenly blowing lots of cold air. I have watched a video on how to on older models but when I went to do it on mine things were different than in the video. Can someone either tell me how to do it or direct me to instructions or a video. Thanks in advance.