That fuse probably powers the radio memory and dash clock...and dome lights...etc...supposed to be hot when the car is off. You might have a failing battery....or a trunk light thats on when the trunk is closed....or the stereo could be sapping too much juice if its failing or something.

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'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
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'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
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