Berlingo M59 Wiring Diagram for Fan cooling

Ok really appreciate all the help! Now let's just theorise for a moment and assume the fan does work at all speeds and the reason the previous owner decided to bypass the system was purely based on the fact that the temp gauge "indicated" the fan wasn't running when in fact the engine temp was simply below 97 but the gauge showed the motor was getting really hot??? (his bypass was simply a single wire from 12v to the relay coil so when you turn ignition on the fan runs full speed and all the time) At the moment I just have my dash switch in that 12v line so I can switch the relay on and off. Now, is there any way to "test" that the fan does work in slow speed (we already know it runs at high speed) otherwise would it doe any harm to run the engine on idle and monitor the physical temperature (maybe take reading off the brass base of the temp sensor where it screws into the thermostat plastic housing?) and the slow fan should kick in at 97 correct? then the full speed fan should kick in at 110 ... I really don't think I have ever had the engine temps at that level as I switch in the fan at an "indicated" 100 which in actual temperature would be much lower. The highest temp that has coolant running inside seems to be the area around the temp sensor and it's both new and working. Obviously for that test I would have the fan bypass disabled What do you think ???
 
Hi OzVTR The loom seems to have a socket which I assumed was to plug in for diagnostics but everything else doesn't seem to have anything to do with the cooling fans at all ... The wire from the fan relay just goes into the engine relay box and picks up 12 v for the fan as he had it running whenever ignition was turned on. What is your opinion on my theory above? If the fan comes in slow and fast then it's purely a gauge issue???
 
The wire from the fan relay just goes into the engine relay box and picks up 12 v for the fan as he had it running whenever ignition was turned on.
As I said, you also need a chassis earth (battery negative) return to get the relay to work. Normally that is supplied by the engine ECU. You can supply +12V all day to one side of the relay but it wont work with out an 'earth'. If you are applying +12V were is the earth coming from, because its not coming from the engine ECU (unless the ECU is faulty). In which case why doesn't the other "speed" run all the time?
As Kenny said I would rip out all that suspect wiring and return it to stock. Have any of the original wires been cut? Can you just remove the new wiring to return it to stock?
YES. I think the temp and fuel indicator fault probably confused the previous owner forcing them to do what they did.
I noticed that you have air conditioning. Does it work? If so the slow speed fan should come on after a few minutes of running the aircon. If no fan comes on...that's a problem. The engine ECU monitors the high pressure side of the aircon lines. The pressure is proportional to the 'load' on the system, the hotter the day the higher the pressure. If you have a look at table 4.1 you can see the fan will cut in at 10 BAR and cuts out at 8 BAR. Although that table is not quite right. Slow speed @ 22BAR?
The little TU3 engines run pretty cool, meaning, if you leave the engine idling it may take 10-15 minutes before the fan would kick in, but it should eventually kick in.
 
Line 1599 to the engine ECU is a fan monitor line. Relay 1509 is the high speed fan relay. Relay 1508 is the low speed fan relay. Power is dropped by resistor item 1506. They are all connected together (and the fan) at splice E151 in the fan wring loom above the fan. If the engine ECU detects that there is no power to the fan when it has commanded the fan 'on' it will not let the aircon run.
 
Ok great. I was assuming the the slow speed fan will not run because as you say it needs a negative from the ECU provided the fan relays have a permanent positive 12v I'll check whether the high speed relay was hard wired to provide an earth so when the ignition is turned on and the engine temp is below the threshold the ECU simply wouldn't supply the negative side at all so the earth/negative has been hardwired ..for that reason the slow speed will never run until it gets a negative which will only happen when the ECU "sees" a temp higher than 92 ... so provided the slow speed relay does have a 12v + I should be able to get it to run by giving it an earth (assuming the vans are negative earth) and the resistor is not faulty . If I kill the high speed relay ( just turn my switch off) and give the slow relay a negative the slow fan setup should run correct ???? As usual awesome help and assistance ..I'll get on it on Thursday as I have two jobs tomorrow (I film funerals!!!) Thanks sooo much for your help and patience and I'll report back on progress and also take a few pics of the loom that sits inside the engine relay box. Edit : Yes the aircon does work and to be honest I forgot to kick the fast fan in and the temp didn't really go up so maybe the fan was running on slow due to the aircon pressure being over 10bar
 
Ok...Good, you seem to have a handle on things. All the statements you made are correct. Yes, van is negative earth.
Given all the info I have so far, I believe there is nothing wrong with the cooling system (electrical) of your van.
Good luck.
 
Getting there slowly!! Yesterday I was running with the aircon and when I stopped I jumped out and checked the fan and yes it was running at middle speed so I know that side works fine ... Have to borrow the IR temp meter on Monday to see if the low speed fan actually kicks in now at around 90 regardless what the temp gauge indicates ... Would measuring the temp right next to the body of the temp sensor on the thermostat plastic housing be accurate enough ??
 
I would expect it to be a few degrees cooler but it should give you a good idea of what the coolant temp is.
The temperature comes from the sensor to the engine ECU then onto the CAN BUS to the BSI and then onto another BUS up to the dash.
You have a brand new temp sensor so its unlikely to be that, or the wiring to the engine ECU or the engine ECU.
HOWEVER to be thorough, you should idle the engine until the fan comes on (as you propose). I wouldn't worry about the IR thermometer you could just idle the engine until the fan comes on.
Ok, I just did a "little" experiment for you.
The ambient temperature ATM is 31'.
I idled the engine, TU3JP (1.4 8 valve same as yours) in a C3 from dead cold for 25 minutes and the fan did not run at all! By the way I have run a similar experiment monitoring the temp via a LEXIA. So I know my car is running perfectly! I gave up and literally ran the car around the block. I pulled into the car port and checked the fan...still not running! I waited 1 minute and 30 seconds, the fan kicked into low. It ran for a further 30 seconds and stopped!
As I said in a previous post these little engines (when running correctly) run quite cool and the cooling system is more than adequate. I have seen a lot of posts on European forums where they complain the fan doesn't come on...DUH!
Another trick you can try is removing the plug from the green sensor. The gauge will go all the way up to hot and your thermo fan should run at full speed.
 
Thanks OzVTR You have been really helpful and I feel I'm getting somewhere now .. Such a pity that I don't have a working gauge and I normally panic and switch in the bypassed fan once the gauge creeps over 100 (indicated of course only) If you stop the van and open the bonnet it seems a lot cooler than most engines after a run. I think I will try your little trick tomorrow by pulling the plug on the sensor and making sure the high speed fan actually kicks in so I know then I can run the motor (with the sensor reconnected) and then see if the low speed comes in and even if it doesn't I know that the high speed will come in later. Will post results!!
 
Let us know where the temp gauge indicates full hot.
"cold" is about 70', is that right?
Sorry but my C3 just has LED "bars". The first bar comes on after the engine has run for a few minutes and 3 bars is operating temperature. It never indicates more than 3 bars and typically doesn't move from the 3 bars.
Your dash is sort-of kidney shaped with the dials arranged (left to right) fuel, taco, speedo, temp?
Looks like your temp gauge should sit at about the 90' mark (1/2 way). Actually a bit less than that, read below.
I have attached a photo of recorded data on a LEXIA session I did.
The top trace shows the outlet temperature from dead cold (ambient temp, about 20') to highway speeds over a 15 minute period (LEXIA will only record a maximum of 900 seconds).
I found it very interesting that you can see the thermostat slightly opening and closing to regulate the temperature.
As you can see the average temperature is about 86'. This is continuous highway driving and not stop start. Although the temp shouldnt vary much in stop start either. I would expect yours to be the same.
If you are interested, the other two traces are of the oxy sensors. In short, it shows the catalytic converter is not working. In fact, as it transpires, there was NO catalytic converter...LOL.
 

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OK I think we has 100% success ... (I have included a photo of my temp gauge so I'm taking the "indicated" reading above 90 as 100 as the next mark and the top mark as 110 before the red area but we know that it's over reading anyway) I used the car as normal but had to go to the shop at lunchtime so left my manual switch off. By the time I got home temp had risen to 110 mark so I left the engine running in the driveway and went to look at the fan and it was still not running so I left it for another minute and it crept up just a tad over the 110 mark when I heard the slow relay click in and sure enough the slow fan was running .. like yours the fan stopped after about 30 seconds and the temp gauge has dropped back to the 110 mark ..I left it again and the fan kicked in as soon as the needle went a tiny bit over 110 mark and cut out as soon as it went back to the "110" mark. so it seems to be working perfectly it seems ..What do you think ...If indeed the highest mark before hitting red is 110 then the gauge seems to be over reading by at least 13 degrees .. (as the slow fan comes in at 97 right?) So without recalibrating the gauge .. can I assume everything is OK as long as the indicated temp stays out of the red ... I honestly think that the previous owner saw the temp almost in the red and decided to run the fast fan all the time!!! Again thanks for the awesome help
 

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What nobody has considered is the actual coolant "brew". Modern systems use the chemistry to raise boiling points as well as resisting freezing damage. There is also the protectant properties of modern coolants too. My Mitsubishi was recalled following a few cases of boiling and head gasket failures ( the result of a batch of poorly machined cylinder heads apparently ).... part of the recall was to reset the temp at which the electric fan comes on ... and here is my point .... to increase the concentration of the coolant which raises the actual boiling point.
 
OK I think we has 100% success ... (I have included a photo of my temp gauge so I'm taking the "indicated" reading above 90 as 100 as the next mark and the top mark as 110 before the red area but we know that it's over reading anyway) I used the car as normal but had to go to the shop at lunchtime so left my manual switch off. By the time I got home temp had risen to 110 mark so I left the engine running in the driveway and went to look at the fan and it was still not running so I left it for another minute and it crept up just a tad over the 110 mark when I heard the slow relay click in and sure enough the slow fan was running .. like yours the fan stopped after about 30 seconds and the temp gauge has dropped back to the 110 mark ..I left it again and the fan kicked in as soon as the needle went a tiny bit over 110 mark and cut out as soon as it went back to the "110" mark. so it seems to be working perfectly it seems ..What do you think ...If indeed the highest mark before hitting red is 110 then the gauge seems to be over reading by at least 13 degrees .. (as the slow fan comes in at 97 right?) So without recalibrating the gauge .. can I assume everything is OK as long as the indicated temp stays out of the red ... I honestly think that the previous owner saw the temp almost in the red and decided to run the fast fan all the time!!! Again thanks for the awesome help
Well at least your engine cooling system appears to be running correctly...even if the gauges aren't.
Yep, just consider "110" as "normal".
So much for the sales man saying "the fans run all the time in Australia". 🤣
Well this should increase fuel economy and alternator lifespan a little bit.:)
I have no logical explanation as to how the gauges are working the way they are. I can only venture that the dash came out of a completely different type of vehicle with different types of sensors. Consequently different 'laws' to run the gauges. IF my proposal is correct that means the odometer may not show the true mileage either.
I have bought many cars second hand over the years and the only guarantee you get is that you will never know everything that the previous owners have done to the car. I have always found they have fiddled with something!
Shout out to Kenny for the diagrams, they were invaluable.
 
Thanks for that and also thanks to Kenny!!! Amazingly enough the RPM and Speedo seem to be accurate but the speed sensor sometimes stops running so the odometer stops too .. the fuel gauge is the same as the temp one ..over reads ..on fill up it goes way over the "F" mark and the orange fuel light comes on around 1/4 tank ... I just wonder if these are not voltage related ? Older analogue Jaeger gauges used to have a 10 volt regulator feeding them so when the alternator is charging the battery the nominal voltage rises from 12 to 13.6 ... the digital gauges use a different method totally but this van has a analogue instrument panel ... My was registered in 2009 but actual year of manufacture was December 2007!! Again really appreciate the assistance and valuable information!!
 
How computer savvy are you?
If you are serious about continuing to maintain your Berlingo and can cope with installing dodgy pirated software, why not get a LEXIA?
I paid about $70 from an Ebay seller here in Aus. Indispensable if a light of some description comes on the dash.
You can also check problems in the back ground that don't bring on a light.
I paid another $70 for an old laptop with Windows XP on it.
The thing I would recommend to you is to ensure you can get a refund from the seller. I have found the hardware can be DOA.
Just something to think about.
The last lot of gauges I had anything to do with were thermostatic gauges in my '84 Ford Meteor (which I still drive). It had a thermostatic regulator that pulsed the power to the gauges about 2 time a second (I think). I calibrated the gauge to the coolant temperature sensor up to 100' (cant get water over 100' at atmospheric pressure...LOL).
I cant tell you how the gauges are driven in your car. There are a number of ways to do it these days but either way they will be directly driven by through a control unit of some description. Any form of voltage regulation will be from an nonadjustable solid state regulator and would not be relevant to any deviation in the pointers position.
I am still of the opinion that there is a very simple explanation for this...like the dash has been changed. I'm not saying that's the only explanation, but any other explanation requires a bizarre and complex series of events to have occurred (like, the needle pointers having been moved).
 
That was going to the next step! I run three machines at my home office and have a funeral and wedding live streaming business (I'm also a computer programmer!) Yeah you would only need a very low spec laptop for that so one off Gumtree would work fine I reckon .. where is the best pace to buy a LEXIA kit ..so far I have only seen them on eBay ??? You did say you got yours on eBay too? Thanks again for all the help and until I can get that I'll keep a watchful eye and make sure the temp cycles no higher than my "indicated 97" Just for interest what does you van usually average in temperature or does your bar display have no degrees marked on it ... I figured that most engines run just below the half way mark on the temp gauge so maybe that would be around 85 ?? so if I add my over-read of 13 mine should hover around the 100 mark I reckon .. I will test it over the week and see .. we are in lockdown for 5 days so not much will happen this week!!
 
That was going to the next step! I run three machines at my home office and have a funeral and wedding live streaming business (I'm also a computer programmer!) Yeah you would only need a very low spec laptop for that so one off Gumtree would work fine I reckon .. where is the best pace to buy a LEXIA kit ..so far I have only seen them on eBay ??? You did say you got yours on eBay too? Thanks again for all the help and until I can get that I'll keep a watchful eye and make sure the temp cycles no higher than my "indicated 97" Just for interest what does you van usually average in temperature or does your bar display have no degrees marked on it ... I figured that most engines run just below the half way mark on the temp gauge so maybe that would be around 85 ?? so if I add my over-read of 13 mine should hover around the 100 mark I reckon .. I will test it over the week and see .. we are in lockdown for 5 days so not much will happen this week!!
Well, then running a LEXIA should be a piece of cake. As I said it's dodgy pirated software but you should have no trouble with that. There can be a bit of farting around with the drivers but I figured it out so you should have no trouble.
I am running mine from a stone age Think Pad using XP and it runs just fine. Apparently you can run it from later versions of windows using virtual machine but (apparently) that can be problematic.
A lot of the ECU updates are done online. So not being official registered software, you cant down load the updates. Having said that, PSA don't seem to update firmware much.
There are two types of hardware, 'standard' and 'full chip'. From about 2010 PSA went to UDP (Universal Diagnostic Protocol...I think it's called that). You need a full chip version of LEXIA to scan those modern cars. For your van you just need the plain vanilla version.
Buy it from Ebay, you get more buyer protection. I got my first one from Banggood. It was DOA and they dumped me like a hot potato! Get it from an Australian seller and contact them and ask them their policy on DOA units before you buy it. Don't worry about the software, there are plenty of versions on the torrent sites. They are all the same Chinese knock-offs with the same pirated software. Unless it's a full chip version pay the cheapest price...they are all the same!
If you do get a LEXIA you should be able to change the gauge 'LAWS' and re-calibrate the gauges. I am very interested in that!
 
I have found that on most cars the temp gauge 1/2 way mark is where the normal operating temperature of the engine is. The gauge on my Meteor indicates 50, 75, 100 and 120, a very similar to range to yours.
With the pointer dead level (indicating normal running temperature) it points to a point about 1/2 way between the 75 and 100 marks.
The digital dash of the C3 only has bars (6) and no indication of the actual temperature at all...just 3 bars = good.
 
Thanks ozVTR We are currently in lockdown in Perth the entire week but I did go to the shop and refuelled the van .. I left the fan bypass off and temp rose very consistently up to around the 100 mark on the gauge and stayed there .. based on where the slow fan comes in I would estimate the actual engine temp to be between 85 - 87 which (if the gauge was reading correctly and not around 13 over reading) would put it just under the mid way point which is pretty much perfect I think ..Our ambient when i went out was a blistering 38 this afternoon too and when i got home I popped the bonnet and the engine certainly felt quite normal. ... I also had a now and again failure of the speed sensor (yes the dealer was supposed to change that but comes up with a hundred excuses. Does yours work off wheel sensors or do you have the one on the bell housing at the back of the engine on the passenger side ... it seems to work 100% from start but sometimes dies on the highway or stays at zero or drops off and suddenly comes back ... I have lived with that as it's only seldom and I can calculate speed from RPM if I need to!

Thanks again for fantastic input!!!!
 
No worries, you are welcome.

The speed in the C3 is derived from the ABS system, from the wheel sensors.
No disrespect, but I find it hard to believe a modern vehicle does not have ABS.
You have checked and there is a sensor above the diff between the two drive shafts? I know we have been through this before but I forget.
If so, have you pulled it out to see if there isn't anything obviously wrong with it?
Yes, I think your cooling system is working just fine. What does the coolant in the expansion tank look like?
In one of your posts you said the temp goes up at highway speeds. Is that still right or just misreading the gauge?
From the pic's you posted, the engine bay seemed quite clean. How does the van look over-all?
 
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