Hi,

So my AC is working as in the heat and the cold both work, however, there is a problem where i can not set any of the vent modes.
ie, face, foot, windscreen defrost etc do not work. those controls do not respond to anything at all.
i can change temp etc but none of the vents.

after driving for a while i then i may see one of the vent modes flick on and off and on and off and then it will work, then after driving again for a while it may stop working again.

my first thought was to do a climate control diagnostic.
however when holding the recirc and auto buttons whilst turning the car on, nothing happens.

to me this points toward a dead/dying AC control module.

 

Quickly a common issue is the center vent thumbwheel , a potentiometer

This mixes the hot and cold streams bypassing the heater core / matrix

The center vent pulls straight out but be careful of the fragile louvers as they age / brittle

You can drive the door / trim motors with a 9 volt battery back and forth

Pic If I can find it

 

AC center Vent Issues - Jaguar Forums - Jaguar Enthusiasts Forum

 

how would this relate to my issue tho?
hot works, cold works.

are you suggesting that the centre vent thumbwheel is somehow sending a signal that makes the control panel inoperable?

 

Standby , fuses?

 

Alot of humidity lately

The foam air seals between the climate control ducts deteriorates allowing drips of condensation that may have wetted the climate control ECU connectors

With a heat gun you may be able to target the connectors as the CC ECU is mounted on the center plenum on the car's / plenum right side under one of the duct's joints

It was very humid up north at Port Douglas years back when there

 

nope.
as said, after driving a bit it may randomly start working in correct operation.

as you can see in my video, the only controls inoperable are the ones to control which vents are open and closed.
all other controls work and the ac unit works. blowing through the face and feet vents.

 

could be bad connection, but i fear the module is ready to say bye bye.
i will be installing speakers and amp amongst other things over the next week so will have a lot of trim out of the way so can easily inspect.

 

Looking at the wiring guide there are a couple of CC ECU ground wires to check for it proper operation

The 2 each wires that drive each door motor open and close do not include a ground but in reversing the polarity so I would look else where

The door position sensors may not be stable from a ground or a common point that they are spliced which are a few plus connectors

 

i would have thought something like a problem with any one of the actuators would stop it from opening or closing not stop the whole system from working.

the part that really confuses me and really makes me think the module is dying is the fact that i can not enter the self test diagnostic mode.

 

ok so.
update.
i got it into diagnostic mode.
i realised that i was holding done recirc and auto and so it wasn't going in.
but then i started tapping them as was turning the ign on and and it worked.

so it was showing err code 24 and 44 but it was not beeping on those codes indicating that they were old errors.

i went through the actuator test and all seemed to be good.
i then cleared the error codes.

after turning the car off and on again i went back to diagnostic mode, all the lights flash to indicate all is good, and no error codes were showing.


after then resetting the car again i was trying to change the vents modes and no buttons were responding,
then after a little while, the one on the far right begins to flick on and off.
then the buttons began working, then they stopped and then that one began flicking again.
ithen the buttons all worked again.

i have a feeling i may have a sticky gunked up button that is causing havok.
sometimes acting as if it is pushed in and therefore disabling the other vent buttons