I

Igor0077

Member
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.
 
Last edited:
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 ?

1724590839885.png
 
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)
 
Sorry if I ask this once more - just to double check:
If I replace my hevac JFC102400 with JFC102550 I don’t have to worry about any damages nor harms, right?
If the aircon doesn’t work anymore I will come back to you and hope one of you guys will have a plan. But for now I would be fine if I knew nothing will be blown when I will go to test the new second hand hevac.

Thanks so much in advance!!

Igor
 
Igor0077 said:
Sorry if I ask this once more - just to double check:
If I replace my hevac JFC102400 with JFC102550 I don’t have to worry about any damages nor harms, right?
If the aircon doesn’t work anymore I will come back to you and hope one of you guys will have a plan. But for now I would be fine if I knew nothing will be blown when I will go to test the new second hand hevac.

Thanks so much in advance!!

Igor
Click to expand...
No problem, you can swap no fear, just check your second hand HEVAC has the same number of buttons on the front or you will be missing some functions.
 
pwood999 said:
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)
Click to expand...
 
So, after quite a while today I received a second hand controler from UK. Unfortunately my issue stayed the same.
So, one simple question (hopefully): Which motor goes to which place? One is marked with blue tape and in my opinion this goes to top right position, yes???
And one more question: Which motor is responsible for which function?

Thanks in advance!!!
 
Can't remember, but I think the the two with Black & Blue tape go on the right side. Distribution motor is the top right on heater box. The two Blend motors are lower down.

The easy way is to check which pins on the connector are used by each motor, and compare with the diagram in RAVE.
 
pwood999 said:
Can't remember, but I think the the two with Black & Blue tape go on the right side. Distribution motor is the top right on heater box. The two Blend motors are lower down.

The easy way is to check which pins on the connector are used by each motor, and compare with the diagram in RAVE.
Click to expand...
Thank you so so much for your help pwood! But I'm afraid I still need some help. I found the attached diagram on Rave but I struggle on two points:

- I have the following cable colors: white, brown, grey, black and red/black. Rave is talking about B,N,W,RB,S ???
- My plug looks like this (attached) and I'm wondering where is number 1 and where is number 16??

Again, thanks to everyone who is willing to give me some support here. This fault keeps me busy since weeks now and I'm slowly losing hope...
 

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Igor0077 said:
Thank you so so much for your help pwood! But I'm afraid I still need some help. I found the attached diagram on Rave but I struggle on two points:

- I have the following cable colors: white, brown, grey, black and red/black. Rave is talking about B,N,W,RB,S ???
- My plug looks like this (attached) and I'm wondering where is number 1 and where is number 16??

Again, thanks to everyone who is willing to give me some support here. This fault keeps me busy since weeks now and I'm slowly losing hope...
Click to expand...
The connector info is in RAVE but here are the functions pin by pin

HEVACConnectors​

CO791 12 pin connector

Pin 1, 2 & 3 Right Blower motor.

Pin 4, 5 & 6 Left Blower motor.

Pin 7 & 8 Ambient temperature sensor.

Pin 9 & 10 Right Recirculation motor.

Pin 11 & 12 Left Recirculation motor.


CO792 8 pin white connector

Pin 1 BECM Feed from RL7– F8 30A.

Pin 2 Engine Compartment fuse box F42 10A.

Pin 3 Engine Compartment fuse box F35 10A.

Pin 4 GROUND.

Pin 5 Heated Front Screen.

Pin 6 BECM (Interior lights circuit)

Pin 7 Aircon RL3


CO 793 20 pin connector

Pin 2 & 10 Water Temp sensor heater core.

Pin 4 & 10 Sun Sensor.

Pin 12 & 10 Evaporator Temp sensor.

Pin 13 & 14 Engine Control module.

Pin 15 & 16 A/C Aspirator dash fan.

Pin 9 & 18 A/C Aspirator dash fan Thermocouple.

Pin 6, 9, 10, 11 & 15 BECM.

Pin 20 Instrument panel Control Unit & Message centre display.

Pin 6 & 7 OBD datalink.


CO1579 16 Pin connectors

Pin 6 & 16 Distribution blend motor.

Pin 2---------------- Red/Black Feedback potentiometer

Pin 15-----------> White

Pin 4---------------- Grey Feedback potentiometer


Pin 9 & 10 Right Hand blend motor

Pin 5---------------- Red/Black Feedback potentiometer

Pin 7-----------> White

Pin 1---------------- Grey Feedback potentiometer


Pin 11 & 12 Left Hand blend motor.

Pin 13-------------- Red/Black Feedback potentiometer

Pin 8-----------> White

Pin 14--------------- Grey Feedback potentiometer

​
 
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