My 2007 Rav 4 heater doesn't work some days it will but most of the time its not

What is your question?

I took my 2008 into vavoline and they recommended their air conditioning service And ever since then it stopped working about 2 months later. Sometimes the heater works only when I turn it on when on the highway

What makes this problem better or worse?

I’m not sure

How long has your 2007 Toyota RAV4 had this problem?

About 2-3 weeks