Every time I turn the ignition on in the wifes A130, there is a clicking noise eminating from behind the dashboard. Its rhythmic and only lasts for about twenty seconds or so then stops. The car drives fine and I am at a loss to find out whats happening.
I can't see it when looking from the engine compartment as it seems to be behind the bulkhead between engine and dashboard.
Does anyone have any ideas as its driving me mad not knowing whats the cause. Is it causing any long term problems?

 

Don't have any specific A Class experience.
Noise will undoubtedly be a relay. What it controls I'm not sure.
Does it do it with the heater/Air Con fan turned off?
I'm sure somebody else will reply with a better answer.
Stuart