flasher for this car for turn signal on 1990 Oldsmobile Cutlass Cruiser

where are the flashers for the turn signals located at on this car

The turn signal flasher should be mounted above the steering column. From under the dash look above the column and you should see the wires going to the flasher. If your flasher is still making a least some noise following the sound will help find it.
1 more answer
Try under the dash behind the ashtray.