Technical Coolingfan is running when engine is cold

[chiquita]

Hi, new here, from Sweden.
My problem is like this:
Fiat Ducato 2,8 tdid -00 Campingcar Hymer with manual AC.

As soon as turn ignition on the coolingfan on the left side starts, not with a high speed but it starts and is running all the time when I drive.

On the upper backside of the coolingfan is a sensor(?) atached se photos.
If I loosen the electric cables the fan stops.
A small sign says 0,23 ohms.
When I messure it I have about 1 ohm (?)

The other sensor down on the left side of the cooler (photo) seems to work ok, cause when I loosen the cables the fan still runs.

Can anyone explain this to me?

I am not use to write english so please forgive me when my english is bad...

/Roy

 

[adlarplant]

if the sensor says it should be .23ohms and you have one ohm the sensor could be faulty my2011 2.3 ducato has had a similar issue and with mine its a fan worn out and shorting to earth usually blows a fuse as well ive found the fans last approx 200000kms hope this helps

 

[fenman]

That looks to me like a resistor rather than a sensor and could be used to vary fan speed. Measuring low resistance values can be tricky as you may have significant contact resistance in the test probes/clips so don't assume the unit is faulty.

I don't know your model but I wonder if the A/C radiator is on that side. If so it could be that the fan will run continuously when the aircon is on.

 

[chiquita]

That looks to me like a resistor rather than a sensor and could be used to vary fan speed. Measuring low resistance values can be tricky as you may have significant contact resistance in the test probes/clips so don't assume the unit is faulty.

I don't know your model but I wonder if the A/C radiator is on that side. If so it could be that the fan will run continuously when the aircon is on.

Hi, know I now a little more.

Yes, it is a resistor for the fan. In a electric schema I saw that there should be a relay (30 A) for each fan.
They are mounted together but I have not yet found them.

Maybe they are situated under the dashboard on the passengers side? se picture.
Anyone knows?

The car is a Fiat Ducato 2000 2,8 Tdid (Hymer 644)

 

[chiquita]

Hi again.

Now I know some more:
A relaybox was attached to the backside of the cooler. In this it were 3 relays. (picture).

The black relay is for the AC-fan (50 A).

The yellow are 30 A each. I tried to shift them left to right but it was the same. As soon as I turned the ignition on the fan starts.

When I removed the right yellow relay the fan was still running but when I removed the left yellow relay instead the fan stopped.

It seemes as it is nothing wrong with the relays.

Could it be the sensor at the left down side of the cooler that is the problem? When I remove the cables from the sensor the fan is still running....
Does anyone know how this sensor should work?

About aircon: in Sweden it is not so warm that I need the aircon. On our 6000 km holidaytrip this summer I used the AC about 4 hours...

Still confused but on a higher level /Roy

 

[Cope79]

Did you find the solution? I have that same problem with my 2.8idtd with A/C...

 

[Communicator]

Did you find the solution? I have that same problem with my 2.8idtd with A/C...

Hi Cope79,

Welcome to the forum.

Before your post, the previous post on this thread was made on 14 August 2013, and the OP has not been seen since September 2017. I doubt that you will get a reply.

If I had your problem, I would start by disconnecting the thermostatic switch on the side of the radiator (cooler).