I cannot get the heater functions to work.

Hi there, Thanks for the question. There are several potential problems that could be the cause of this issue. The ideal thing to do is to bring it in to the repair shop to have it properly tested to determine the exact source. There may be switch problems or it could be something in the climate control unit or possibly something wrong in the wiring. A visual inspection and/or possibly some partial dash removal may be required. Thanks again,