hey so im at a stand still. i have a 99 durango and have an issue with very little heat. i have replaced the water pump, and thermostat. i flushed my heater core and radiator and my coolant levels are fine. my radiator cap though is not getting hot what so ever and my temp gauge in the car will only go up to about 170 max. does anyone have any other ideas's as to what it could be.
I believe the mix door is vacuum operated. On my 2000 the lines that go to it are under the drivers side dash toward the center console.
I would think if the coolant temp will not get over 170 then i would suspect the thermostat is stuck open.
Did you use premixed coolant or mix it yourself. If it isn't mixed properly it can cause problems.