Locating hidden lighting relays.

[driver0606]

Some of the lights on my Azimut 43 and various other Italian boats are operated by hidden relays. I can hear the clonking as they operate, but cannot accurately determine their positions and there are no visible inspection panels. I dread the day when the clonking stops, together with my last hope of finding the little devils.
Any ideas, please? Is there perhaps a device that will locate the magnetic field that would presumably be created as they operate?

 

[Rocksteadee]

Some of the lights on my Azimut 43 and various other Italian boats are operated by hidden relays. I can hear the clonking as they operate, but cannot accurately determine their positions and there are no visible inspection panels. I dread the day when the clonking stops, together with my last hope of finding the little devils.
Any ideas, please? Is there perhaps a device that will locate the magnetic field that would presumably be created as they operate?

Operate each one, listen for the relay click and note which panel it is behind.
It is easier to find it now, rather than when it does not click

 

[driver0606]

My thoughts exactly. Unfortunately both my wife and I are unable to find the noise source with any accuracy. Maybe the panels (which would in the main, be very difficult to remove) are dispersing the sound.
Hence requesting any ideas about locating equipment, rather like that used to detect wires in walls. Although cheap, all the wiring detectors I have seen only work with AC.