Headlight relay

A clicking relay is normally the relay itself so I will attach the info below on this, but this could also be a connection issue or even a grounding issue.

Since the switch is on the ground side of this circuit then the switch can be the issue as well.

What I would suggest is to replace the relay and here is a guide that will help with testing and replacing:

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

If the relay is not the issue, then just go to the bulb and back probe the ground side of the socket and supply it straight to ground. If the relay stops clicking, then you most likely have a switch issue.

Take a look at this info and let us know what you find. Thanks