Audible 'Lights on' warning system

[Cam]

Just in case anyone missed the thread in 'Elecrical'

To create an audible 'Lights on' warning system like modern cars have:

Get a 12v buzzer from Maplin electronics, RS etc. (they are about £1).

On a negative earth car:

Connect the black (-) wire to the door switch, and the red (+) wire to the sidelight live, and hey presto.. door buzzer!

On a positive earth car:
as above but swap + for -

It only gets a live when the sidelights are on and only gets earthed when the door is opened, obviously it needs both to operate which it gets when the sidelights are on AND the door is opened!

Those buzzers are quite loud (and sound right) and only draw a tiny current, well within the operating load of the operating courtesy switch.