Citroen Berlingo not preheat

Hello everyone for a long time I did not connect was lied with the work.
My problem is that a 1.9D berling with 15 years came to workshop. Proven warm -ups and well, I thought I was wrong to put a new one and it remains the same.
Looking for Google apparently is typical failure but not found the answer.
Does anyone know what else do I have to look?

Some carry a probe in the thermostat box so that the preheating when it is cold (not to confuse with the probe temperature for the box) if it carries it you can try unplugating it, or bridging the connector to see in which in the two ways it acts, I suppose that when he will warm up it is when the probe opens the circuit so that when you return to start hot it no longer acts or do it less time. Greetings Igryo!

Thank you, notice that I think about it because you also have problems with the temperature needle, it goes a bit crazy. On Monday they bring it to me again I will focus on the temperature sensors.

I will have to be careful I do not want the vehicle to think that it is always cold or hot and the arrangement is worse.
all the best.

You will have to replace it (the bridge or disconnection is only to try) I think the one that affected was green. Greetings!

It is already solved, they brought it to the week. It was a round connector that is a little below the relay and has 5 or 6 cables, it was to clean it with clean contacts and everything works ok. perfect temperature and preheat.