How to tell if your vent is closing all the way?

[happydog500]

On my car, when I put the vent on, the air is warmer then the outside. I realize the air going through the car may be a little warmer, so I'm not sure if it's at the normal point, or if it is warmer then it should be. I'm wondering if my vent has a little more it could be closing, letting in warmer air.

How do I check to make sure it's closed all the way?

Thank you,
Chris.

[rustbucket]

Its a little overkill, but harbor freight sells an inspection camera for 119. possibly you could snake it into the vent to see the door closing.

[imidazol97]

Originally Posted by happydog500

How do I check to make sure it's closed all the way?

You can check the vent movement by taking off the underdash plastic shield, possibly taking off the glovebox door which requires 5-6 screws and then watching the movement of the electric actuator on top of the HVAC box. You watch how it moves the metal rod link and the plastic that it snaps into that is the lever for the vane inside the HVAC box.

You can also turn off the key after moving the temperature and the link to one extreme, preferably HOT. Then unsnap the arm and move the arm inside the box yourself. You'll feel it hit the end of the movement in the hot direction. Then snap the metal rod back in.

A first check would be is the heater core stopped up. Open the hod and feel the heater hoses after the car has been driven 15-20 minutes and make sure both are hot, almost as hot as the lower radiator hose, after driving. With the blower on high wait a few minutes and check to be sure the radiator hoses are both almost equally hot. If the core is partly clogged, the low water flow means the water gets cooled by the air too much and the water leaving in the return hose will be noticeably colder. Sometimes having someone run the motor at 1500 or so while you check the hose will increase the flow and the temps will be about the same.

Also make sure the level of coolant in the reservoir is at the right mark and with the engine cooled down open the radiator cap itself on the radiator to make sure the coolant in the radiator is full. Low coolant will leave an air bubble in the heater core, but still won't give overheating symptoms.