Dear Doctor: I own a 1999 Dodge Ram 1500 pickup. I cannot open the door with the key in the cold winter months. I’ve tried all kinds of oils, but none seem to work. Do you have any ideas? Bill
Dear Bill: The best product I have used to lubricate door lock cylinders over the years is Lock-Ease graphite lock lubricant. This lubrication can be used on all door lock cylinders, including home door lock cylinders. Never use any regular motor oil on door lock cylinders. It will thicken up and jam the tumblers.