It could be the flasher or the signal relay switch. You could take it to NAPA or Advantage and they would answer this question for sure for you.
where is location for fuse or whatever makes the turn signals work. they turn on but do not work
To change the turn signal flasher in a 2002 Cadillac Seville, first, locate the flasher unit, which is typically found under the dashboard, near the steering column. Remove the panel covering the area if necessary, then unplug the old flasher by gently pulling it out of its socket. Insert the new flasher into the socket, ensuring it is securely connected, and replace any panels you removed. Finally, test the turn signals to ensure they are functioning properly.
It is located under the dash on the drivers side, mounted on the passenger side of the steering wheel. There are 2 flashers there. One for the turn signals and one for the hazard lights.
In a 2002 Cadillac Seville SLS, the component that controls the turn signal indicators, or blinkers, is located within the multifunction switch, which is mounted on the steering column. This switch is responsible for activating the turn signals when the lever is moved up or down. Additionally, the flasher relay, which helps control the blinking rate of the signals, can typically be found in the fuse box under the dashboard or in the engine compartment.
First off your vehicle has two flasher relays. One for the turn signals and one for the hazard lights. Both Relays are located under the dash on the drivers side mounted on the passenger side of the steering wheel. It simply plugs in. Go buy a new one and you will know what is looks like or click the link to see a photo of the relay.http://www.autozone.com/electrical-and-lighting/relay-turn-signal/duralast-relay-turn-signal/cadillac/seville-sls/1996/8-cylinders-y-4-6l-sfi-dohc/221854_0_0/
Turn signals and hazards are two separate curuits. Check/replace your signal light fuse and flasher.
There are two relays, one for the emergency flasher and one for the turn signals. Replace the Flasher Relay for the turn signals, it is defective.
The flasher is a type of switch that regulates the turning on and off of your vehicle's turn signals and hazard signals.
Flasher and fuse
It is possible if the flasher relay is going out or has gone bad.
Faulty Turn Signal flasher Faulty Turn Signal Switch
replace your flasher relay