Ducato Burstner Camper Repair Main board

Dear Sir or Madam,

I kindly ask for your assistance with diagnosing or possibly repairing the main control board of the electrical installation in my 1992 Citroën C25 Burstner motorhome.

When I bought the vehicle, I received the original control box, but the main board was disconnected and undocumented. Based on online photos, I was able to reconnect it according to visible wiring patterns, but unfortunately the system does not function correctly.

Observed symptoms after connection:

I can hear the relays click, but they are disconnected after about 1 second,

The ON button lights up only while being held – releasing it turns off the power,

I verified the battery (placed close to the board), voltage, all connections, and wiring,

I also disconnected the 230V input and all connected devices/sensors – no change.

Unfortunately, I do not have any technical documentation or wiring diagram for this board. So far, I have only found partial information on French forums.

I’m attaching a video recording showing the exact behavior of the controller when powered.

Is somebody has scheme for main board please let me know .

Thank you in advance for your time and kind support.
Best regards,