i have a 300E / 1990. it has developed a tick-tick-tick noise in the foot area onthe passenger side. It very noticable when i put my ear close to the foot vent area. i have removed the glove box and checked the aspirator motor. no problem there. the noise is there after the key is turned to position #1. At this position, the engine is not even running, but all the lights on the dash are lighted up. The noise does go away after a while (10-20min). but it is so annoying. What componets are in that area and can cause a noise like that? any help is appreciated.

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96 E320