Change Hevac Controler

I need to change my hevac controller. Motors are new but book symbol stays on and distribution motor doesn‘t work.
I have unit JFC102400. All I find is JFC102550.
What do I have to convert to make this newer unit work??

Or does anybody have JVC102400 for sale? I‘m in Germany, so Europe would be great!

Thanks in advance!

The later JFC102550 is supposed to have an extra relay for the compressor clutch. Some people (including me) have found it works fine without the relay in 1997 or earlier cars. After 1998, land rover added a relay to provide better voltage to the compressor.

When you say the "motors are new", do you mean brand new from LR, or used replacements ? It would help to have Nanocom diagnostics done to be sure.

Hey Pwood, thanks for your reply. „New motors“ means they are realy new (Valeo).

I don’t understand the relay thing.

Nanocom doesn‘t see any faults.

So, what exactly can I do?)

Have you tried Nanocom output menu to move motors and engage the compressor ?

Also the compressor not engaging could be the clutch or low AC gas. Both can bring on book symbol with HEVAC in Auto mode.

Just plug the new one in, it will do no harm just the aircon might not work depending on the year of the car. Then you can post me the old one to fix (I'm in France). A late model HEVAC should work in an early car but an early model HEVAC will not operate the aircon in a late model car without some changes.

Datatek said:

Just plug the new one in, it will do no harm just the aircon might not work depending on the year of the car. Then you can post me the old one to fix (I'm in France). A late model HEVAC should work in an early car but an early model HEVAC will not operate the aircon in a late model car without some changes.

Click to expand...

Hey Datatek, that sounds like a plan. Merci!!

Do you actually have Nanocom communicating with HEVAC. If distribution motor doesn't work there should be a at least a fault for that showing? Does the Inputs menu show when you select the direction buttons ?

I habe Nanocom Communication but no faults. Good point to check the inputs. Will do tomorrow!

Also try using output to drive motors & see if feedback responds.

Now I checked every single option Nanocom offers.
Input: Everything says GND.
Output: I can check some lights and the front windscreen -all okay.
Utility: Can force every single motor. Still distribution motor doesn‘t work.

There are still no faults visible on Nanocom but book symbol on hevac is on.

After I changed the whole set of motors two times in the last week (always brand new Valeos) and the distribution motor works when I put it under 9volts from a battery, I still believe that the controller is the problem here.

Does this make sense??

Thanks to everyone involved!

Yes. A known issue is the driver chips failing (I have one on the bench waiting for me to change the chip !).

Regarding the Inputs screen. The buttons should all show GND, but change to 12V when you press the button. That's how you test the inputs !! (Note: other ECU inputs vary, where some are 12V default and GND when pressed)

I had this recently, my left hand blend motor driver had failed inside the hevac.