Thumbs up TESLA HEAD UNIT intermittent AC FIX!!!Hello All,
I know this thread is a few years old, but I recently purchased and installed the Tesla unit in my car. I was inspired by my friend, neighbor and Forum member, MARQUE.
Two years ago, I watched MARQUE install his unit and he was having the intermittent AC problem. I had the same problem the other day when I installed mine. So, I set about to figure it out and find a fix. As I was troubleshooting, I was thinking that maybe the modules in the trunk might be the issue. So, I contacted the seller about it and he confirmed my suspicions, Then I unplugged all the modules and guess what....IT WORKED!!! I called MARQUE and told him. He unplugged everything, and guess what..... IT WORKED!!!
So, I suggest to anyone still having the AC problem. Just unplug modules in the trunk and you should be good..

 

Hi, I have the same issue after installing the head unit in my XJ8.

Essentially the aircon hunts constantly and will not settle down at all.

Before I wast time contacting the vendor in Mainland China, what modules in the trunk did you unplug ?

While looking for the mystery modules I could hear the relay near the battery (obviously for the aircon) clicking every couple of seconds. It is obviously not happy.

Many thanks !

Paul

 

I also have the same style tesla headunit and my issue is more that the AC is constant when the car senses a certain temp. I rather that than intermittent though. After unplugging the trunk modules does yours now run constant if adjusting at the headunit, not seeing any change in output?

 

I have installed same Tesla unit in spring 2023. I removed navigation, CD changer and amplifier completely, call it weight reduction.
I do not see any problems with HVAC in the car.

 

I do not know what modules to unplug in the trunk but can certainly unplug and remove the amp, cd and navigation units that are redundant.

I did notice the can bus unit decoder supplied says “S-Type” (which my car is not). I have contacted the vendor to see if this is correct or whether this is the reason my aircon is freaking out.




Thanks for the assistance guys.

The unit certainly functions fine apart from this one issue. Having CarPlay in the car is great.

 

The issue has been solved ! The mystery modules in the trunk / boot are the ones that are no longer required such as CD changer, sat nav, phone.
Once these were disconnected the aircon settled down and the controls now work perfectly.
The original vendor was very helpful and had me try a few things (selecting XJL on the car selection) before the tech said unplug these units in the boot.
I have attached pictures.

Picture 1 from the vendor

Picture 2 from the vendor

CD changer, satnav and old phone modules

Back of the satnav unit, same as the one they suggested unplugging

Back of the cd changer and 2 phone modules