Solved. Volvo S60 wonky AC

[meep]

2005 Volvo s60 with 175k. It’s a true road warrior, love this car. Was mine and is now my daughters. shes complained the AC just won’t cool, that it takes different combinations of tweaks, which then shift and changes, and still never gets cold.

so I took it for a drive today. For a long time I’d noticed the ambient air temp would read around 6F. It was 84, and the the knob set at 72 it was nearly blowing heat. At 66 it acted like 74, and at full cold it felt like about 72. what clued me in then, was that the ambient air temp might rise and fall 10 degrees, and when it did that, the blend doors in the dash shifted. Aha!

google foo demonstrates much debate on which mirror Volvo sticks their ambient air sensor(s) in. The internet has decided on whichever side has the steering wheel. Mine appears to have 2. As soon as I disconnected the drivers side mirror, the temp correctly popped up to 84… which was odd because without the mirror and it’s sensor, how would it know? Either way, i metered the temp probe, it was good, cleaned all the contacts with deox spray, put it all back together and now it has AC.

takeaways. Volvo has at least one, and maybe two, exterior temp sensors. They are mounted in the side mirrors, and if they go wild, the interior climate control loses its mind.

 

[Number_35]

2005 Volvo s60 with 175k. It’s a true road warrior, love this car. Was mine and is now my daughters. shes complained the AC just won’t cool, that it takes different combinations of tweaks, which then shift and changes, and still never gets cold.

so I took it for a drive today. For a long time I’d noticed the ambient air temp would read around 6F. It was 84, and the the knob set at 72 it was nearly blowing heat. At 66 it acted like 74, and at full cold it felt like about 72. what clued me in then, was that the ambient air temp might rise and fall 10 degrees, and when it did that, the blend doors in the dash shifted. Aha!

google foo demonstrates much debate on which mirror Volvo sticks their ambient air sensor(s) in. The internet has decided on whichever side has the steering wheel. Mine appears to have 2. As soon as I disconnected the drivers side mirror, the temp correctly popped up to 84… which was odd because without the mirror and it’s sensor, how would it know? Either way, i metered the temp probe, it was good, cleaned all the contacts with deox spray, put it all back together and now it has AC.

takeaways. Volvo has at least one, and maybe two, exterior temp sensors. They are mounted in the side mirrors, and if they go wild, the interior climate control loses its mind.

Nice bit of troubleshooting!

 

[Oro_O]

Thanks for passing that on. Have not heard of this problem before on the Volvo forums. Duly noted.

You may know this, but another source of cc behavior oddity in the P2 cars is the cabin temp sensor on the center console. It's behind that little slotted grille on the cc head unit. Dust (pet hair especially) accumulates on it over time and can also drive the cc crazy. A blast of compressed air usually fixes it vs. taking the head unit out and cleaning it directly.

 

[meep]

^^^ shot of air performed. Good tip!