My heater box is located on the starboard side of the fuselage. The heater duct runs through the side of the forward baggage compartment to an eyeball vent close to the pilot's right knee. The control cable is located next to the vent and is labled "cabin heat". I set the cable up so that you pull for heat and push the knob turn the heat off.
The control cable comes through the firewall just above and to the left of the heater box, loops down under, and attaches to a bracket on the right side of the box. I will be adding some plastic or nylon tubing over the steel cable conduit and anchoring it to the motor mount to guard against chafing.