Normally my Berlingo (2.0 Hdi) doesn’t get the chance to get warm enough to require the cooling fan on the radiator to kick in, as it is used for a rural commute. Last week I had to drive into Glasgow. Sitting in traffic the fan would kick in for 2 or 3 seconds- literally just spin up, then back down. I’m guessing that the ECU was telling it to kick in, but there must be a latching relay or something that is not working.

I reckon the sensor must be working as the fan was commanded to come on, and that the fan actually works because I heard it, even if only briefly. By elimination, I have arrived at the relay… only I don’t know which one, or where it is. Haynes manual is not helpful.

Any tips?

Quite a common fault, cooling fan resistors on the front panel in front of the radiator corrode badly and cause all kinds of of fan faults.
If you remove them 1 or 2 depending on A/C or not
They have the 0ams resistance on them.
So easy to check/test if faulty and about £15 each to replace.

I do have a/c. Are both identical?

Can be depends on age of the van. I’ve been away for 2 weeks on holiday, e mail me your reg I’ll check for you.

It turns out to be the resistor unit that is mounted in the radiator fan unit. I thought I had bought like-for-like, but the one that came out has 0.54ohm resistance, and the replacement 0.8ohm.
I’m not sure how this difference will manifest itself.

My van cycles the cooling fan like that when the air con is on…

It’s a Citroën relay tho

The gubbed resistor was stopping the fan running properly. I disconnected the coolant temp sensor and started the engine. Temp gauge went straight to red, STOP light started flashing, but no fan. When I changed the faulty unit, the fan started straight away. I have reconnected the coolant temp sensor, and will go for a test drive tomorrow.