Electrics stay on with key out

Here's a headscratcher (for me).
Peugeot 405 GT TD estate.
All the electrics stay on, even with the ignition key out.
I had to disconnect the battery until I had time to take it to garage.
They've narrowed it down to the circuit which does the central locking,
rear screen wipe, interior lights and ABS, and pulled the fuse.
(SO I'm without them while electrician is away for a few days. The radio
works but needs the code putting in each time. The ABS light stays on
but sometimes flickers).
Does this ring any bells?
Thanks and cheers!

 

It rings a bell from when I owned and loved my 1992 VW Corrado SLC. The
fancy aftermarket alarm system failed and caused the same symptoms that
you described. It also caused the electrics to just flat die on the
road a couple of times. Failure of the ignition key module can also
cause it to occur. Good Luck!!

 

That's an interesting idea. I guess the car must have an alarm. But I
have never had a blipper key and never used it in the six years I've
owner it. Will pursue ...

Meanwhile I can now put the radio code in each time without even looking