You can fix this for free if you are careful. Pull off the black box that controls it and take it apart. There are lots of little tiny springs and balls, so do it in an area where you can't lose anything. The connections over time get junk on them, or the balls fall out so you lose the electrical connection. Its a common thing.

Everything is very logical if you just spend some time looking at it.

Tackle this before going further.

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2016 Monsoon Gray Audi Allroad - 21k
2008 Black Mercedes E350 4Matic Sport - 131k
2014 Jeep Wranger Unlimited Sahara - 62k
2003 Gray Mercedes ML350 - 122k