Clicking noise

raisincain

when I turn key to start car there is a loud clicking noise somewhere behind the glove box, it quits after a while, what is the problem?

Mr_Shiftright

Sometimes relays will react to voltage drops, so it's possible that circuit (whatever it is) might have corrosion or connection issues. The relay in question is apparently not getting a constant voltage supply and thus can't operate properly.

It's also possible that the clicking noise is not a relay but a malfunctioning motor for the HVAC air diverter (blend door).