Headlight relays clicking and lights flickering (even when the key is out)

Started my Legnum up tonight after it sitting idle for a few months. Charged the battery back up and then it wouldn't start due to low fuel pressure so a fuel filter change sorted that.

However, after finishing that and starting it up I noticed that the headlights were flickering whilst engine was running. This then contained when the ignition was of and the key was out. Both the sidelights and the high beam relays were clicking away like crazy.

I don't suppose anyone has an idea on the cause of it. I want to start driving it again but this will obvious kill the battery pretty quick.

Cheers all