Fiat Siena Diesel 1997 Buijias warming

Hey Marmol you have taken the heater and tested them, it can be the sensor as Angel says but check the wiring well and the signal must reach the switchboard, your switchboard should arrive if I am not mistaken six cables some of them is the temperature sensor.- Greetings.

Angel, yours was spectacular !!!! unplug the bulb and, if the witness light lasts the mimsm time (13 seconds) than the preheating. I thank you.
The other issue would be to solve whether the damage is the broken bulb or the cables, because I tell you this:
according to the car manual says: that the witness light goes out when the temperature reaches the established and the luminous signal also has a diagnostic function to indicate possible faults of the water temperature sensor and/or the corresponding electrical circuit.

My final question is the following that already present in the forum: Why does the engine heat me if everything is fine, my supposed answer is that when the bulb or electrical circuit fails it causes the problem in the thermostat?

thank you

Angel gave on the key, all sslio well fixed that I wrote to him, the switchboard arrives five cables (six no), but your participation is very good and that of all who have collaborated in this forum.
Look to leave other prutons to Angel.
thank you so much