Technical X250, 3.0 2013 with aircon, blower fan speed not working at position 4

[Tulleke]

Hello,

I bought a Ducato X250 3.0 from 2013, I thought I checked everything from the interieur fuctions but overlooked to test the interieur fan at position 4.

When I turn the fan switch, speed 1,2 and 3 are working fine. At speed 4, the aircon light turns off and the fan stops. I have checked following already: I replaced the fan resistor and I did some measurements at the fan switch. Fan switch is working in all positions. I also shorted a wire between pins 1 and 5. Pin 5 contains a smaller wire, I think it will go to a relay or something. I also checked all fuses from engine and passenger compartment.

One sidemark, I think the airco doesn't has enough gas because it's not cooling. I hear the airco pump is switching on when pressing the airco button. But would like to fix the fan speed 4 first

 

[Communicator]

Hi Tulleke,

I am puzzled by your statement that there is a thinner wire on pin 5 on the control switch. This would fit with the diagram for an x244 aircon system, where pin 5 of the switch does operate a relay. In this scheme fan speed 4 is switched by a relay, so as to take a supply from maxi blade fuse F05 (40A), in the engine bay fusebox. On speeds 1 to 3 the fan motor is powered via a different fuse (F55).

On the eLearn diagram for the X250 aircon, it shows the fan motor being supplied from fuse F05 on all 4 speeds with no extra relay involved.

Perhaps there is another version of the wiring, or is it possible that the aircon has ben added to your vehicle, after it was built?

I will attach a link to a diagram of the x244 version, in the hope that it may help.
http://4cardata.info/elearn/244/2/244000001/244000003/244000005/244001985

 

[Tulleke]

Hi Communicator,

Thanks for your answer! Yea it's indeed strange, fan speed 4 has a smaller wire and it's definately a x250. I checked the fan control wire again and I followed the wire bundle. Then I saw a cable going to the front, below sigarette connection. This cable has an empty single relay foot. And it contained the same wire color as from fan speed 4. So I took a relay from the motor fuse box and fan speed 4 works! So It looks like it's a x250 with 244 cable?

 

[Communicator]

Hi Tulleke,

The question posed in your final sentence gives rise to more.
I am surprised at your ability to trace a cable bundle with such apparent ease when access is so restricted, but then aircon is an optional fitment, so perhaps a completely separate bundle.
The diagram for x244 aircon shows 3 relays located somewhere. I assume that these are mounted in the engine bay, perhaps under the plastic hood at the rear. (My x244 does not have aircon, so I cannot check.)
Relay J034 puts the fan on speed 1 when aircon is switched ON.
Relay J041 is the fan speed 4 relay.
Relay J022 operates in parallel with J041, and switches the fan motor positive supply to fuse T05 when speed 4 is selected.

To answer your question, check that your vehicle has all three relays.


There is an error in the eLearn drawing at the connections to relay J041. The two wires shown as connecting to terminals 5 & 3 have been incorrectly crossed. The circuit will not work as shown.
There is another error at relay J022, where the Bosch style contact designations need rotating one step anticlockwise. (To be correct C=30, NO=87, and NC=87a.)

 

[stezie]

Hello! I would like to follow you progress on this. My van is the same, the previous owner placed some tape over the number 4 indicator on the dial( ambulance service! ).

I was going to buy a new resistor for this, as I wasn't aware that there could be a relay.

Are you able to locate the position of this relay?

 

[Communicator]

Stezie,

This is just a short post to make it quite clear that the resistor is not used for fan speed 4.

As to the relay location Tulleke has not made clear,the location of the relay socket that he found. I do not have aircon, but I have suggested that the relays may be under the plastic hood (screen wiper cover) in the engine bay.

 

[Tulleke]

Hello again, day two, and I opened the dashboard again to check if there are more missing relays. I followed the wire from the fan switch to the fan motor and the fan resistor. There's only one relay for fan speed 4. All other, 1, 2 and 3 are directly connected with the resistor. I measured them. And cable 1 from the fan switch is directly connected with the minus/chassis. I also don't hear any relay when activating fan speed 1. There's also only one fuse which operates the entire fan system. The location from max fan relay is just between fan speed switch and the glovebox. I have no idea if the relay foot should be mounted somewhere. Hopefully everything is clear. See attached pictures

 

[Communicator]

Tulleke,

Many thanks for the interesting photos. Much has been revealed, including to me, the source of the relay socket numbers on the x244 eLearn diagram E6020. I now fully understand that the relay is just hanging in the wiring. The location of relay will be of interest to stezie.

I think that the relay is fitted to help preserve the fan speed switch from the full speed current taken by the fan motor. The relay is not shown in the eLearn information for the x250 aircon, that I had previously saved. Perhaps it is this eLearn document that is incorrect. The diagrams are not very clear, but I will attach it here. (The date on the document pages is from when I downloaded it, possibly from this forum.)