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HVAC Air/Vents not working correctly

N

notamos

NAXJA Forum User
Location
Fort Collins, CO
I put a new heater core in last fall & have had a few problems since. I'm hoping one of you may have an idea what is going on.

-HVAC controls on the defroster only, it works properly (dash vent only)
-HVAC controls on the defroster/floor setting, it works properly (dash vent and floor, 50% each)
-HVAC controls on panel only (just air or AC), it works properly (panel vents only)
-HVAC controls on floor only, it blows out the panel vents 50% and the floor vents 50%

It is possible I hooked up something wrong but I'm not sure where to look. The blend door is operating correctly and the control seems to be working properly as it moves the actuators when I move it to each position.

Its bugging me because when I put it on the floor, I want it to blow there only. I hate the 50% mix.

Any thoughts on this?
 
notamos said:
I put a new heater core in last fall & have had a few problems since. I'm hoping one of you may have an idea what is going on.

-HVAC controls on the defroster only, it works properly (dash vent only)
-HVAC controls on the defroster/floor setting, it works properly (dash vent and floor, 50% each)
-HVAC controls on panel only (just air or AC), it works properly (panel vents only)
-HVAC controls on floor only, it blows out the panel vents 50% and the floor vents 50%

It is possible I hooked up something wrong but I'm not sure where to look. The blend door is operating correctly and the control seems to be working properly as it moves the actuators when I move it to each position.

Its bugging me because when I put it on the floor, I want it to blow there only. I hate the 50% mix.

Any thoughts on this?
Click to expand...

Here's a schematic of the vacuum system.

Look at selection 7 and 8/10. Somehow vacuum is being applied to the Panel Actuator (f) when the Floor Actuator (c) is selected (?)

Both actuators require vacuum to be applied to them in order for them to open.

Note also that the Defrost Actuator is being powered closed at the same time (Defrost Actuator opens the defrost door when vacuum is removed from it.).

Do you think that the foam seal on top of the HVAC Unit that surrounds the defrost door may have been skewed when you put everything back together (air leaking past the defrost opening to the floor chamber)?

jpgModeSelectFunctions.jpg




HVACUNIT5.jpg
 
Last edited:
notamos said:
Great idea on the seal being skewed... I am pulling the box out this morning and will report back.

Thx!
Click to expand...

Verify that the vacuum tubes connector on the back of the Mode selector is secured and the vacuum tubes quick disconnect is secured before pulling the HVAC Unit.

You may be able to get a look at that seal area (a bit) by removing the radio and top dash panel.

Backof99ClimateControlPanel-1.jpg


DSCF2611.jpg


DefrostValveaccesswithradioremoved-1.jpg
 
First - Thanks to SWCC for the awesome replies. I was able to check out all of my connections and determined that I still had something going on. So, I pulled the HVAC box and tested it outside the vehicle (using the switch and the vac line from my cruise).

Anyway, when I replaced my heater core back in the fall, there was a piece that I had no idea where it went. Well, it turns out I put it back in wrong. It was keeping the panel door from closing fully - causing the air leak.

Here is a link to a post regarding the mystery piece: http://www.jeepforum.com/forum/f11/heater-core-hvac-box-reassembly-886449/
 
notamos said:
First - Thanks to SWCC for the awesome replies. I was able to check out all of my connections and determined that I still had something going on. So, I pulled the HVAC box and tested it outside the vehicle (using the switch and the vac line from my cruise).

Anyway, when I replaced my heater core back in the fall, there was a piece that I had no idea where it went. Well, it turns out I put it back in wrong. It was keeping the panel door from closing fully - causing the air leak.

Here is a link to a post regarding the mystery piece: http://www.jeepforum.com/forum/f11/heater-core-hvac-box-reassembly-886449/
Click to expand...

That's good info to know.

Glad it's fixed.
 
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