Hello. I have a Volvo 2006 xc70. My heating and AC systems do not work. However, once every few months, they suddenly are able to work for few days. As in, the ***** on my dashboard begin working, so I can adjust the fan settings. And I do in fact feel the AC and heating air, so I know there can’t be any leaks. This tells me it’s something to do with the computer chip or wiring. Also, this oddly occurs when it’s cold outside usually.
This makes me think there is some disconnected wire or short or something that’s causing the issue, and it sometimes “is fixed” in rare situations. Then after a few days, the system stops working.

I took my car to the shop, and they said it’s likely that, and that ordering a new dashboard system would cost 2 grand since my dashboard parts “aren’t made anymore”. I was wondering if there was a way I could take everything out, diagnose it, and see if I could fix it. Has anyone had this issue before?

 

A good first step would be a scan of all the control units - in particular the Climate module. Those codes if any might point you in the right direction. With a good scan tool/Vida you will be able to activate components (turn compressor on, fan on, check switch positions, etc.) to verify what works or where the problem might be. Sure it's possible you have a bad climate control unit, but if it's just the fan that does not come on - (as you said "And I do in fact feel the AC and heating air") - the fan resister/fan motor/or a melted/bad connection is a possible culprit.

These folks can fix or provide you with a replacement CCM if needed. They really want a VIDA readout first - to make sure they fix what's really needed. It is easy to replace your climate module - just a few screws and 1 electrical connection - BUT If you disconnect the module with the battery connected - you will set a SRS (airbag) code that will require a scan tool to reset the srs code.

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