One problem related to air brake hoses, lines/piping, and fittings has been reported for the 1996 Mercury Sable. The most recently reported issues are listed below.
The outer door handles become inoperable when the vehicle is left in the rain. Condition varies from totally inoperable to difficult to open. The vehicle opens easily from the inside. It has also happened once on the front left door. The dealer never heard of that happening before. If you slam the door real hard it fixes itself. When the condition goes away the doors open like new again until another rain.