You can find several relay switches on your 1990 Cadillac Sedan Deville. Most relay switches will be in the fuse box. The relay switches will be in the third column of the fuse box.
Should be on top of the starter
I'm going to assume that it is similar to the cover on the 1997 Deville Concours. In the '97 you simply 'pull up' on the cover. It has prongs that press and snap into receiver ports in the vehicle proper.
There is no relay. They are wired directly to the headlight switch.
The 2004 Toyota Tacoma flasher relay fuse is located beneath the drivers side dashboard. The flasher relay fuse is actually a relay switch.
The 1995 Mercury Villager turn signal relay switch is located beneath the drivers side dashboard. The turn signal relay switch will be left of the brake pedal.
The windshield wiper relay switch, on your 1999 Cadillac Deville, are located mounted to the firewall in the engine compartment. The relay switch will be next to the windshield wiper motor.
The 1999 Cadillac Deville headlight relay switch can be found in the fuse box. The headlight relay switch will be in the third column, second from the top.
Where is the field park relay on a 1993 Cadillac Deville
Located under the hood left hand side(Drivers side) labled fuel pump relay. owners manual will show this
The 1987 Cadillac fuel pump relay switch is located in the fuse box. The fuel pump relay switch will be at the top of the third column.
The blower motor relay on a 1980 Cadillac Coupe Deville is situated on the passenger side. It is located in the vicinity of the firewall and is just below the windshield.
There are many relays in that vehicle. Need more info.
under hood, passanger side, under relay panel cover, beneath it, almost next to firewall.
trying to find fuel pump relay on my 1994 cadillac deville
the compressor relay is in the underhood fuseblock drivers side of the engine compartment.
The fuse is next to the parking brake. If it has a relay, its in the under hood relay box near the windshield wipers.
A 1998 Cadillac Deville does not have a blower relay. The system has a fuse and a controller to feed power to the blower motor.