Technical Year 2000 Ducato fan running in middle of the night!

[Madmike]

Been a while since I posted here and now I'm in the commercial section!
I have a Motorhome on a 2000 Fiat Ducato 2.8D (not the turbo version)
Because this problem could happen with any Ducato, I'm posting here, but mods feel free to move to motorhome section if it should be there.

I bought this about a year ago and have always noticed that the cooling fan cuts in at very low temperature and seems to run most of the time when driving, but I always reckoned it was better to have a fan running too much, than not at all!

Last night about midnight I could make out a hum outside my house and went outside to find it was sitting there with the cooling fan running. It hasn't been started or driven since last weekend, so I have absolutely no idea why it started this all of a sudden.

In the dark and so late at night, I just unplugged the fan and it sorted the issue rather than disconnecting batteries etc
Tried plugging it back in just now and it immediately runs again

There seems to be a plastic box on the fan shroud that the plug cable runs back to
I'm assuming this is a relay or relays in there?? The top of the box feels warm
Just posting here to see if anyone has any idea what I should be looking for or what has possibly failed

Many thanks

 

[Communicator]

A 2000 2.8D will be an x230 model, but in the abscence of an appropriate wiring diagram, I can only speculate as to the operation.

On my 1990 Talbot Express the two cooling fans were controlled via relays from the ignition switch and a thermostat low down on the vehicle RHS of the radiator.
I needed to replace the thermstat, due to faulty operation.

I do not know whether whether the thermostat location was changed between 1990 and 2000, but on my 2.8jtd the coolant flow thermostat and temperature sensor are at the No.4 cylinder (clutch) end of the engine.

In @Madmike 's vehicle I would expect two relays, one for each fan. The relay coils could be supplied via the ignition switch, with the other end of the windings connected to earth via the thermostat contacts. However with the fans running with ignition off, it suggests two coincident faults. On later vehicles the ECU can operate the fans for several seconds after tne ignition is turned off. Perhaps this has been implemented with a timer for the fans when the ignition is turned off? Another if, is has this timer also failed so that the ignition control for the fan relays is permanently live. That is sheer speculation.

Perhaps there is a simpler answer? Possibly a wiring short in the fusebox. It is hard to know without a diagram.

The thermostat is already suspect. This can be proved by locating the thermostat and disconnecting it. The hypothetical timer is more of a problem.

Is it possible to open the black box to reveal the contents? (I nearly called it Pandora's box.)

 

[Madmike]

@Communicator Many thanks for your response

As it turned out an awful evening here with rain, I didn't get to do much with it since
I did however manage to open Pandoras Box!
It's exactly as you describe with the previous model and yes, mine is the X230
There are 2 relays inside and the one on the right hand side when looking into the engine was red hot as it seems it was energised since this happened last night, so I swapped it with the other relay to see if anything changed, but the fan still ran when I plugged it in again, so I'm assuming both relays are fine and it is indeed related to a sensor as you mentioned

From what I could see briefly, when looking into the engine, there is one sensor on the bottom right of the radiator just below the fan that is giving trouble and I think there is possibly one or two sensors on the thermostat on the block also. I can take better pictures tomorrow to show the layout of everything.

Regarding what you mentioned about the timer, the only thing I know is it would quite regularly run for 4 or 5 minutes even after turning off the ignition, and on one or two occasions, even after switching off, it would briefly cut in again after a minute or two and run for maybe 20 or 30 seconds. I never questioned if this was the standard setup, or if indeed someone had at some stage installed some kind of timer like you suggested

 

[Communicator]

@Communicator Many thanks for your response

As it turned out an awful evening here with rain, I didn't get to do much with it since
I did however manage to open Pandoras Box!
It's exactly as you describe with the previous model and yes, mine is the X230
There are 2 relays inside and the one on the right hand side when looking into the engine was red hot as it seems it was energised since this happened last night, so I swapped it with the other relay to see if anything changed, but the fan still ran when I plugged it in again, so I'm assuming both relays are fine and it is indeed related to a sensor as you mentioned

From what I could see briefly, when looking into the engine, there is one sensor on the bottom right of the radiator just below the fan that is giving trouble and I think there is possibly one or two sensors on the thermostat on the block also. I can take better pictures tomorrow to show the layout of everything.

Regarding what you mentioned about the timer, the only thing I know is it would quite regularly run for 4 or 5 minutes even after turning off the ignition, and on one or two occasions, even after switching off, it would briefly cut in again after a minute or two and run for maybe 20 or 30 seconds. I never questioned if this was the standard setup, or if indeed someone had at some stage installed some kind of timer like you suggested

I was trying to make the distinction between a thermostat as a temperature operated switch, and a sensor with variable resistance with temperature, a measuring device, as used for the temperature gauge.

The device on the radiator is most probably a thermostat controlling the fans via the relays. Mine had three wires as earth return not good on radiator with rubber hoses and mountings. If possible disconnecting any two wires should kill both fans. Logic/trial and error may allow one fan to be restored. I still have the one removed from my 1990 vehicle many years ago. 29mm across brass hexagon, black, white, and red wires. Black & white share a polarised connector, red is single male connector. If this seems to the correct item, Peugeot/Citroen part number was 1264.10.

I was thinking that the timer could be original.

Rhetorical question now is where is the timer or whatever is used to retain the supply to the relays? Alternatively could the fans be controlled only by the thermostat, then faulty thermostat would explain all.

 

[Madmike]

Many thanks for the response, but unfortunately it looks like it could be Tuesday afternoon before I will be back at it again

I'll post back here with any findings and hopefully try figure out what exactly is going on

 

[Madmike]

Ok, just about managed to get underneath it this afternoon while the ground stayed dry before yet another few torrential downpours!

Unplugged the cable going to the switch/thermostat in the bottom right hand side of the radiator
Plugged the fan back in and plugged the relay back in and no fan starting up, so I'm assuming that proves my cable is ok

Got back underneath the radiator and went to plug the connector back on to the switch/thermostat and instantly once I touched the contacts, the fan started running again, so I'm assuming this means that the radiator thermostat as you described needs replacing.

I've had a look using my VIN on Eper and for the 2.8 Ducato (non turbo), it gives me switch no 7738582 and a quick Google gives me these, which have a 29mm brass nut, so I'm guessing thats the one I need

 

[airwave]

I was thinking that the timer could be original.

Hello mate , just for your info , i have found no evidence of a timer on the cooling system circuit of this particular model . I have just completed an extensive rebuild of my vehicles cooling system , same model , same year . Further evidence is should my fans be running on shutdown (very rare) , the fans also instantly switch off . The sensors mentioned by @Madmike , are as best i can uncover , part of the high temp , gauge warning circuits . One being described as a refridgerant temperature sensor , which i assume is the temp gauge sender , and the other interruttore pompa acqua e tubazioni , which roughly translated , is a water pump switch . The interesting thing here , is the water pump like many vehicles of this age is engine driven , via the crankshaft . So i'm not totally certain what this thing does actually switch , but i assume it's a function i've not seen yet . Some kind of separate warning light for instance , similar to the low oil warning system ? .
Now the wiring diagram i have here is perhaps a bit suspect , but the initial feed for the cooling fan relays is from the ignition switch , via fuse one , and the instrument cluster , but the interesting thing here is , the wiring diagram shows two supplies direct to the thermostat . Whereas you quite rightly have stated there are only three terminals in total , and i can confirm that , two of those terminals to the relays . Further , i'm in the process of fitting a fan manual override to my cooling system , and my understanding is the relay interruption is via the ground signal , but i can't fully confirm this at this time . My understanding is , this is a perfectly normal method of connection , as it protects the sensor from the high voltages present at the fans themselves .

 

[airwave]

so I'm guessing thats the one I need

Check your actual sensor colour , but using my van same model (but with an intercooled motor) , same year , as a bench mark , you should be using the blue sensor . Notice there are two for this vehicle , and the difference is the temperature range , notated by colour .

 

[Madmike]

Interesting that you mentioned the colour, as I was looking at those and most appeared to be blue and I literally just went back underneath to get photos there now and the one that's in it is a black sensor, but looking through the ones I found on that page, I see that some operate from 82-92 and then 92-97, while others are 87-92 and then 92-97, but it seems that both black and blue vary with the temps

 

[airwave]

Interesting that you mentioned the colour, as I was looking at those and most appeared to be blue and I literally just went back underneath to get photos there now and the one that's in it is a black sensor, but looking through the ones I found on that page, I see that some operate from 82-92 and then 92-97, while others are 87-92 and then 92-97, but it seems that both black and blue vary with the temp

Now that is interesting , as when i last brought one , i was given the option of two . A blue one , which is what was fitted , and i think black ! . When i asked what the difference was i was told temperature range . I just replaced like for like , and had a blue one .

I really can't advise further , as your van is a 2.8 non turbo , and my van is a 2.8 intercooled turbo .

 

[airwave]

Okay just had a look at my manual , i should be using a sensor with an ;

• Opening temperature of 95c/99c (1st and 2nd stage) .
• Cut off temperature 91c/95c (1st and 2nd stage) .

 

[Madmike]

As they aren't expensive, I think maybe I'll pick up 2 of them, so I can always swap one out if I have any issues

 

[Madmike]

Okay just had a look at my manual , i should be using a sensor with an ;

• Opening temperature of 95c/99c (1st and 2nd stage) .
• Cut off temperature 91c/95c (1st and 2nd stage) .

What manual are you getting that from if you don't mind me asking?
I'd like to have a manual for this for any other bits that come up

 

[airwave]

What manual are you getting that from if you don't mind me asking?
I'd like to have a manual for this for any other bits that come up

It's part of the pocket manual series by Peter Russek , only one i could find for this model . There's a lot of holes in it , but i'm used to working with diesels . I'm not a professional by any means , and i do come unstuck at times , but it is a little bit of help at times . Problems with it are no pictures at all , diagrams are not always clear , no torque values , and the text can leave large chunks out . For instance , no mention of either a turbo fitting or intercooler for my van . Seems more aimed at the non turbo 2.5/2.8 , But frankly , it's better than nothing .

Just had a quick look on ebay , and theres nothing there , so ;

• www.russek-manuals.co.uk
• ISBN 1-898780-94-3
• Citroen relay/Peugeot boxer/Fiat ducato
• from 1994 2.5/2.8 litre diesel

 

[Communicator]

Hello mate , just for your info , i have found no evidence of a timer on the cooling system circuit of this particular model . I have just completed an extensive rebuild of my vehicles cooling system , same model , same year . Further evidence is should my fans be running on shutdown (very rare) , the fans also instantly switch off . The sensors mentioned by @Madmike , are as best i can uncover , part of the high temp , gauge warning circuits . One being described as a refridgerant temperature sensor , which i assume is the temp gauge sender , and the other interruttore pompa acqua e tubazioni , which roughly translated , is a water pump switch . The interesting thing here , is the water pump like many vehicles of this age is engine driven , via the crankshaft . So i'm not totally certain what this thing does actually switch , but i assume it's a function i've not seen yet . Some kind of separate warning light for instance , similar to the low oil warning system ? .
Now the wiring diagram i have here is perhaps a bit suspect , but the initial feed for the cooling fan relays is from the ignition switch , via fuse one , and the instrument cluster , but the interesting thing here is , the wiring diagram shows two supplies direct to the thermostat . Whereas you quite rightly have stated there are only three terminals in total , and i can confirm that , two of those terminals to the relays . Further , i'm in the process of fitting a fan manual override to my cooling system , and my understanding is the relay interruption is via the ground signal , but i can't fully confirm this at this time . My understanding is , this is a perfectly normal method of connection , as it protects the sensor from the high voltages present at the fans themselves .

As @airwave has stated that he can find no evidence of the conjectured timer, then it is necessary to find another cause for the fans running with the ignition off.

The other two "sensors" mentioned could be for the temperature gauge, and as suggested a excessive temperature warning indicator. My 2.8jtd has a combined sensor and thermostat for these functions.

It is standard practice to control the fan relay coils by the ignition switch on the positive side, and via a thermostat on the negative side. (On common rail engines with ECU, the negative side only is controlled by the ECU, which allows cooling to continue for a short period after switching the ignition off. The reason for the relays is to handle the high currents taken by the fans, and not the voltage.

 

[jackwhoo]

Shall we call the temperature dependant switch screwed into the radiator a thermo-switch

The fans starting after vehicle stopped could be caused by heat soaking from the engine into the coolant raising the temperature of the thermo-switch to it's on position.

I vaguely remember a vehicle with fans that would start after engine stopped if hot....Citroen zx may be or golf mk2 or Skoda felicia

Lots of vehicles have warning stickers "fans may start at any time"

 

[airwave]

Shall we call the temperature dependant switch screwed into the radiator a thermo-switch

Yeah i agree with that . I noticed where one post i made , it looked more like i was talking about the actual thermostat , which is a totally different thing !

 

[Madmike]

Shall we call the temperature dependant switch screwed into the radiator a thermo-switch

The fans starting after vehicle stopped could be caused by heat soaking from the engine into the coolant raising the temperature of the thermo-switch to it's on position.

I vaguely remember a vehicle with fans that would start after engine stopped if hot....Citroen zx may be or golf mk2 or Skoda felicia

Lots of vehicles have warning stickers "fans may start at any time"

Thermo-switch is good for sure as I feel calling it a thermostat, I might mislead others who find this thread to start examining the thermostat on the engine block

I do know in my many years driving that I've come across a few vehicles before that the fans would continue to run when the ignition is off, but I can't remember what they were and for that reason, I suppose I just assumed it was standard when it happened on this as it's the first Fiat Ducato I've ever driven and with it being 23 years old, didn't really surprise me.

Normally it will carry on running for 2 or 3 minutes after turning the ignition off, so it IS possibly on a timer, but when it ran again a second time, this only happened once or twice in the last few weeks, so maybe it was possibly just because that "thermo-switch" was on the way out

 

[Madmike]

It's part of the pocket manual series by Peter Russek , only one i could find for this model . There's a lot of holes in it , but i'm used to working with diesels . I'm not a professional by any means , and i do come unstuck at times , but it is a little bit of help at times . Problems with it are no pictures at all , diagrams are not always clear , no torque values , and the text can leave large chunks out . For instance , no mention of either a turbo fitting or intercooler for my van . Seems more aimed at the non turbo 2.5/2.8 , But frankly , it's better than nothing .

Just had a quick look on ebay , and theres nothing there , so ;

• www.russek-manuals.co.uk
• ISBN 1-898780-94-3
• Citroen relay/Peugeot boxer/Fiat ducato
• from 1994 2.5/2.8 litre diesel

Thanks for the info. I'll keep an eye out for it anyway as every little bit helps

 

[airwave]

Thanks for the info. I'll keep an eye out for it anyway as every little bit helps

Yeah i've being trying to find a copy , but the truth is i can't even find a record of it even being published . Very strange as the isbn should take me straight to it .
The link won't work , i've tried it , but if you change manual to books you do get a hit , but even here i can't find the book .

I purchased it off ebay , about 4years ago .