G-Funk

I have a 2000 XJ. Warm air is constantly coming into the cabin of the vehicle from the floor vents (I think) unless the ac is turned on. It is not really blowing as if the fan was on, more like leaking. Both AC and heater work fine. Is that a blend door failure?

RTorrez1

More then likely you are correct thinking that it's the blend door.

Jooman07

Does everything cycle between vents like its supposed to? If not then it may be stuck and you should check the vacuum lines first which help control them.

G-Funk

Everything works with the vent selection, however, I will probably take a look at that anyway.

CCKen

Here's how to check your Blend-Air Door actuator:


Place the blower speed switch to low blow,


Select any position on the Mode Selector except OFF,


Turn the ignition switch to RUN (no need to start the engine),


Position yourself in the passenger foot well and look up to the left corner under the HVAC Unit. You will see the Blend-Air Door actuator (see schematic below),


Turn the temperature control **** stop-to-stop (Red/Blue),


You should see the intermediate drive shaft turn slowly from stop-to-stop (watch the slot in the bottom of the shaft).


If you don't see the shaft turn, either the actuator motor is inop or the Blend-Air Door is stuck.


Turn the ignition off and remove the actuator/motor assembly. Leave the electrical connector plugged in. Turn the ignition back to RUN and move the temp control again to see if the motor works. If not, replace the motor. If it does move okay, then try moving the door shaft. If it doesn't move, the door is stuck.


Going back on with the actuator, run it to full HOT (red), then turn the door shaft fully Counter Clockwise, assemble the actuator/motor to the shaft/HVAC housing. Test the actuator/motor again to see if it moves as required.

Fred/N0AZZ

Just what I would have said.. .......right!

G-Funk

Thanks! I will do that and update. Has anyone used this product? http://www.heatertreater.net/


It is a way to replace the blend door with a metal one without tearing apart the entire dash.

cliffpenick

It may not be coming from your vents. Do you have a manual Trans? I was getting the same thing in mine and it was crazy hot. I took the center console out and found that the shifter boot was ripped open letting hot air in. totally fixed it after i installed a new one from the dealer. There is also fire wall plugs that can pop out causing hot air to come also. Might want to check that stuff.

peligro113

This may be a stupid question but is your temp control on hot or cold? If it is on hot coolant will flow through the heater core whether the fan is on or off and since air will continue to come through the cowl into the passenger compartment you will feel that hot air. I place mine on cold.

Waynerd

What about the door that is located behind the glove box. When the hvac **** is turned to off the door closes. It looks like it keeps air from the blower area from entering the vents. Looks like when it's closed all the air would blow by behind the glove box. The blower motor can be seen through vents when off. When turned on the door cover those vents.

Waynerd

Waynerd

U can kinda see the blower wheel through those vents. Dark green vac line on left. Actuator is connected to the arm on the right

CCKen

I haven't used this but I've read reports on forums that they have had luck using it.


Waiting for results of the test I showed you..... :-)

CCKen

The Recirculation Air Door will not block any vents. It's there to direct inlet air to the blower from the outside of the Jeep or from the inside of the Jeep (Recirculation Air).


See the pic showing the lower half of the HVAC unit and the Recirculation Air Door.