Hi guys, I've just changed the thermostat on the van, as it wasn't getting up to temperature properly. Starts up ok with no leaks but have an engine light on and the fan is running from startup. Have run a diagnostic and got temp sensor fault. I've changed the sensor but is exactly the same. I've checked the wiring to the sensor, which seems ok. Have removed relay 7, so fan is still running but just not full speed.
Have left it running to try and bleed the cooling system but the gauge isn't moving at all. Any ideas would be helpful please.

Your vehicle symptoms point to directly to a fault with the temp sensor circuit.
Possibly broken wire inside insulation close to the connector for temp sensor.

What year is your doblo?

Strange if an electrical fault occurred after swapping a thermostat

(Could just be sods law though.. )

Did you drain all coolant.. or leave the cap on?

Check the electrical pins in the temperature sensor are not bent and check connectors in the plug that connects to sensor. I think it is impossible to connect the plug the wrong way round but check this too.

It's a 2010 model. I popped off the lower radiator hose and washed it through from the top. I'll have to check the pins on the connector but it went back on ok as it came off. Will also pull back the insulation and check the wiring.
From reading up on it, the fan is controlled by the ecu, is that correct?

Moin.
ich hätte das Problem auch ich hab das Thermostat komplett neu gemacht und das Problem ist weg

TRANSLATION:

Good morning.
I had the same problem, I completely redid the thermostat and the problem is gone