Heater problem

NavigatorV8

Registered
in the morning time, if my heater runs with full power, will happen the following sometimes:
after several miles, suddenly the vents blow cold air in the cabin. After pressing of different switches at the DATC the vents blows warm air again.
But not always, sometimes everything is okay, sometimes this fault.
What can it be?
It´s a Navigator from 2004
 
Back
Top