Yes, they do.
headlight relay location on a 2004 mercury grand marquis
Where is the headlight relay for a 1991 mercury Capri
In the relay box next to all the other relays.
how to remove right turn signal relay on 1986 mercury grand marquis
Shiny square box on drivers fender near headlight.
It is a module under the dash.
The 1999 Mercury Grand Marquis air suspension relay switch can be found on the firewall in the engine compartment. The air suspension relay switch will be on the passenger side of the firewall.
Replace the flasher relay if none of them are working.
it is on the firewall and difficult but not impossible to get to and replace.
On a 1998 Mercury Grand Marquis : In the fuse panel under the dash : ( # 16 is a 20 amp fuse for the cigarette lighter and emergency flasher relay )
it's your headlight switch
Mercury Marquis was created in 1967.