Dash rattle in 82 500sl. Heater flap?

[Damian]

Hi Guys,

Was just wondering if anyone has had a problem with the internal flap inside the heater box causing a rattle when you go over bumps etc?
I have looked everywhere else inside the dash and can't find what's causing it. It actually sounds like the windscreen wipers rattling about, but I have since removed them. The sound still seems to come from the top of the dash somewhere so I thought it could be coming out of the demister vents. Any leads or help would be appreciated as it's very anoying to hear and makes the car sound old and cheap.

Regards

Damian