Product review (5 stars): Really easy installation. Hardest part (and it was easy) was ...
Had no clue as to actual cause of problem.  Inexpensive enough to give it a try. Really easy installation.  Hardest part (and it was easy) was swapping the original model specific plastic with the generic plastic that came with the new part.  New part had exactly the same mounting as 2003 original.  Seemed exactly the same mechanism as original.  A video I found online said that pulling the AC cord for a moment after installation resets something.  Not sure if this was necessary but all works.  Fast easy fix.  Amazon was one third the price of the local parts store.  Easily saved $200-$250 over the cost of a home service call.