Citroen Berlingo i call her christine lol

Check for water getting into fuse box and this ,

"
Read your post on your problem with your berlingo van,
I had one in with the same problem, head lights coming
on when you open door and heater fan and the only way
to turn them off quickly was to turn the ingnition on,there
was resistance on the White and red can wires between bsi
and engine fuse box mine was in the White wire just about
12inchs from front fuse box



Just fixed one today and it was the exact same wires and area as above post!
If your Citroen Berlingo or Peugeot Partner 2003 (1.9 WJY engine and possibly similar), headlights stay on and heater blower and horn do not work then it will probably be due to the two Can Bus wires (red and white twined together) which run from the black fusebox under the (UK) driver steering wheel (Bsi module) to the passenger side engine bay fuse box which is also the Bsm (another body control module).

You'll probably see in the engine bay near the passenger side headlight area, that the wires have gone green in an area about 12 inches from the plug (which is top left in the engine bay fuse box). Remove what's left of the insulation and then cut & re-join the wires, removing the corroded area. It should immediately fix the above problem. We were told it was a Bsm module (which thanks to lazy Peugeot Breakers was impossible to find, and cost £400 brand new). Thanks to Peugeot Planet 2000, I was able to see the Bsi Fault code. "