Electro valve and heater, how do I try them?

Hello everyone:
I have a Renault Express Diesel 2000 and the heater that would automatically turn on sometimes do not work. Also today I did not take off the electro valve, I had to put a direct and started cable. Suggestions ...? How is the electrical scheme? Thank you.

Hi Edacasta, I don't have the scheme, but just tell you that these cars are usually spoiled the contact box that carries the contact key.
From the anti -theft, a tension for the electrovalvula and for the preheating relay.
For your check you have to use a series lamp or a voltimeter: on the one hand between heater and mass; and on the other between the electrovalve and mass checking that they have a tension when putting the contact.