It's electronically controlled by the PCM, so if it quit working, then most likely it is going to have to do with something wrong inside the transmission. About all you can do is check the fluid level. After that, it will probably need help from a good "trustworthy" transmission shop.
location for fuse, and relay switch on a Mercury Sable
how do i change out a power steering switch on a 2001 mercury sable with a 3.0 engine?
The 1993 Mercury Sable backup light relay switch can be found beneath the drivers side dashboard. The backup light relay switch will be above the accelerator pedal.
On a 1996 Mercury Sable : The fuel pump shut off switch ( inertia switch ) is in the trunk , behind the trunk liner on the passenger side ( there is an access hole )
On a 1999 Mercury Sable wagon : The fuel pump shut off switch ( inertia switch ) is in the cargo area , behind the service panel on the passenger side
In a 1999 Mercury Sable the fuel pump shut off switch ( inertia switch ) is located behind the trunk liner , on the right side ( passenger side ) There is an access hole
On a 2003 Mercury Sable sedan : The fuel pump inertia switch ( shut off switch ) is in the trunk , on the passenger side of the trunk , behind the trunk liner ( there is an access hole )
under dash on drivers side
Overdrive is the normally allowed position . It won't shift into overdrive until the speed is higher anyway , such as on the highway / freeway
The O/D OFF warning light in the bottom left of your tachometer on your 1999 Mercury Sable means that the ( OVERDRIVE IS OFF ) * that's the " top gear " of your automatic transmission
I have the same problem on my 95 Sable LTS
On top of the steering wheel column