I have a 94 SL600 that spends alot of time sitting in the garage. When I take it out, I hear a clicking noise coming from inside the dash on the passengers side. I pulled the air bag and found the noise was coming from a black "box" mounted right below the Air bag unit. I didn't try to get it out but it feels to have vacuum lines running off of it. The sound will eventually go away after 30-45 minutes. Not sure if it's due to low vacuum, a leak, or defective part. I'm hoping someone here will have an idea for a "fix"

 

Bump....anyone have an answer?