Sonata 2000 - Small pulsing device (pump?) behind NS headlight - What is it?

Turning the ignition key on a 2000 Sonata yesterday, without
starting the engine, I heard a clicking sound from the engine
compartment. Lifted the bonnet and found a small pump-like device
behind the headlight. I disconnected it and the clicking stopped.

Please, anyone. What is this device? A diaphragm pump, for what?

 

If this is on the right side of the vehicle, it's possible it's the
alarm siren.

 

No. it's in the left (NS/UK). Sorry my info is so sparse and lazy,
I'll get a better look at it soon. My first thought was that it was
the central locking pneumatic pump which could easily be a diaphragm
type and therefore make a pulsing sound - but the central door locking
still works afer my dsconnection Being close to the headlight I wonder
if it something to do with the steerable (fog?) light.

 

Diaphragm pump for door locks? Have not heard of those being used for years.
You say you have a steerable fog light? Is it a Studebaker?