reptitive aux start clicking

[Selurgniman]

So, yesterday my daughter was jumping around the coach as young children do and she pressed the aux start switch on the dash. Now every ten minutes or so for the past day, the solenoid clicks one time. The switch still works, pressing it causes the same noise but doesn't change the periodicity of the repetitive noise. The house and chassis batteries both read 13.1V and they're only eight months old.

Any ideas?