I "fixed" mt TomTom car dock. I had to look vary closely in the port on the iPhone to see that dust, (pocket lint?) had built up and gotten compacted, preventing the plug from seating properly.
I noticed that ANY charger cable that I plugged into my iPhone was sitting crooked. It would charge, so I didn't think too much about it.
Then I took a look in the slot in the bottom of the iPhone. It looked dusty. I took a wooden tooth pick ane started pulling pocket lint out. I swear I got a bushel basket of lint out.
Now, not only do the charging cables seat squarely, they go all the way in, not just half way.
And the dock once again works. I can charge, use the navigation app and play iTunes through the dock.