On the end of your gear selector lever ( PRN etcetera ) is the transmission
control switch . Overdrive is the normally allowed position , but when you turn
the overdrive off ( the O/D OFF light will light up just above and to the right of
the speedometer and if you have the digital dash it will show " overdrive off "
to the right of the speed indicator )
If Its an older Grand Marquis its easy. Find the knob that you pull out to turn on the headlights. Now, just turn it clockwise and the light will turn off!
There is a switch in the glove box to turn it off.
Leave OD on during regular condition driving to conserve fuel economy. Turn off OD to accelerate better and when climbing hills.
No, just the opposite. Overdrive is an extra gear, the use of which, make the vehicle more economical.
Check the fuse. If it has a manual OD switch to turn off and on be sure it is on.
Have vehicle scanned to determine the problem
Mine is a '97 so not sure if yours will be the same or not, but mine is located on the end of the gear shift lever; there's a little button right on the very end, and you push it in once to turn the OD off, push it again to turn it back on.
No,they won't fit.
If the light says off then your overdrive is turned off, push the button again and the light will turn off and overdrive will be on again.
diagram a\c system 1999 grand marquis online
don't know.
bad fuse or bad switch