Sheepy

Hi all. Recently installed this double din kit and everything works great except one problem. The heating on the HVAC unit now does not work The aircon, fan and everything else works fine, just not my heating for some reason. I have a single zone unit as I am in Australia and my car is single zone. It should just be plug and play as it is a Japanese made Subaru. If anyone has any advice I would appreciate it so much. I have done everything I can possibly think of and it's damn cold at the.moment.