I have a 2002 Montero Sport. Recently when using the heater I can hear the fan ticking noice through my radio. Increased fan speeds and radio volume control makes it seem the fan and radio have merged. What’s up with that?!
The fan in the heater motor has a field winding. This field winding might have a small short in it. One of the main sources for radio interference is a electric motor that’s bad. The only option may be to replace the fan.