Overheating & part number question

[Landmark]

Hi Folks,
2002 Berlingo Multispace 1.4 petrol WITH aircon.
Several times we have had a problem with overheating. In 2010 a garage replaced the temp sender, but I'm not convinced it's the correct one. It's blue with 3 pins but there are only 2 green wires connected to the connecting plug.
I replaced the thermostat last Nov, which seemed to cure it, but now with the hot weather it's started overheating again when in slow traffic.
I've looked at replacement senders on the internet and all seem to only have 2 pins.
Can someone please confirm part number for;
1. Correct sender unit
2. Correct connecting plug
3. Wiring diagram (Haynes manual confusing)

I suspect the problem is the fans aren't comming on but as it's always the wife driving solo I'm not there to confirm this. Also what difference does it make having aircon as to which sender is fitted?
Many thanks,
Griff :wave:

[Rustscrat]

Hi, if you PM me your Vin No. I'll see what I can dig out.:thumbsup:

[Rustscrat]

Hi, The temp sender listed for your engine is part No. 1338 A6.
It should be blue with 3 connections which only pins one and two are used.
Have a look at the diagram, item 1220 is your temp sender and 4025 is the oil temp thermal switch. These go straight into your engine ecu and it is this which switches on your two fans via relays installed in the radiator housing.
Are your fans coming on when the engine over heats??
alut:
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[Landmark]

Many thanks for the info Rustscrat.
As stated in original post it's always the wife driving when it overheats and I'm never there to see if the fans come on. I'll tell her to check next time it happens and be back in touch.
It appears to be the correct sensor then?
Regards,
Griff:thumbsup:

[Rustscrat]

No worries, let us know if you want the fan diagrams.alut:

[Landmark]

No worries, let us know if you want the fan diagrams.alut:

Yes please. It would be useful to save time if I do need them and I've got them already.
Griff

[Rustscrat]

Here you are. alut:

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[Landmark]

Hi Rustscrat, Quick update.
Did long run yesterday (2hrs) and left car outside garage whilst unloading. Went to put in garage shortly after and on turning on ingnition and starting car temp gauge/stop light indicated overheating. After a few seconds immediately returned to normal. Checked fans straight away and not running. Fuse ok.
To me this would seem some fault in the sensing system and not actually overheating as surely it wouldn't suddenly return to normal especially without the fans operating?
Regards,
Griff

[Landmark]

Hi Rustscrat,
Quick update. Wife driving again at the weekend and it indicated overheating on 2 occasions after a long run and in slow traffic. She always turns the internal heater on full when it happens and this appears to cool it. Again she was not in a position to get out to see if the fans were running.
I wish I had a thermal temp gauge to check the actual temp at the thermostat housing. If I had what should it be about?
Regards,
Griff

[Rustscrat]

Hi, something I noticed at the weekend, had the engine out to sort out a few things, put back in but forgot to plug in the water temp sender.
Immediately after the engine fired up the fan kicked in, temp gauge in red.
plugged it back in and after a few seconds everything normalized and fan switched off.
Might be a good way to see if fans work whilst stood?
Also you may have a bad connection somewhere?
But if you say temp comes down after internal fan is switched on I would make sure the radiator fan works first. alut: