If you can't get to the rear of the light in the trunk, the light assenbly has to come off.
PLEASE DON'T TRY TO TAKE LIGHT ASSEMBLY OFF, damage is very likely!--for concise directions on how to change from inside trunk, see the answer to "how do you change turn signal lamps both front and rear on a 96 Mercury Grand Marquis" here in Wiki s (the answer is titled something about an Inside Job if that helps you to locate it).
assuming you mean the light bulbs, see the answer to "how do you change turn signal lamps both front and rear on a 96 mercury grand marquis" right here in WikiAnswers.
The repair section on autozone.com explains how to change the light switch.
I have a 1998 ford grand Marquis- and the problem is the air suspension light stays on- how to fix this problem
take it to a good mechanic or a ford or merc dealer and they have to clear it for you
Have the codes read.
Why ? Just replace it.
Fuse, loose connection, or the light switch. how do you remove the dashboard on a 94 mercury grand marque?
You won't know until you get the code read.
where dose daytime running lamp module go on92 mercury grand marquis need to replace one
where is the running light sensor on a 2003 grand marque
check the bottom of the steering column
Have vehicle scanned to determine the problem