My wife has a 1997 Audi A4 - 6 cyl. The heat is not working properly. Even with the heat on high it barely blows lukewarm air. Her mechanic told her that it is some kind of module that controls that and several other functions and the module itself costs around $400 - $500. Are there things I can check myself to see if it's something else. Can those free diagnostic checks they do at PepBoys tell me what the problem is? There is anti freeze in the radiator and the heat works a little but just barely.:banghead:

I think you should got it checked by some another professional. I don't think that it cost that much.