I believe on that model you can access the signals by lifting up the trunk carpet and then unscrewing the plastic wing nuts. The light assembly can then be removed for easy access to the bulbs.
Sounds like you need a new flasher.
Blown bulb.
The power steering reservoir is located low behind the right side of the motor very close to the fire wall on 1998 Buick Lesabre.
10w30 says it right on the oil cap.
Refer to dash removal of a '94 Lesabre. The only difference is you have to remove a the glove box and the vent to the right on a '93.
More then likely it needs to be replaced, if its the actual signal inside the car, turn it on check outside the car which one it is and replace!!
ensure all bulbs on bumpers are good
There is a bulb holder below the headlight bulb holder on the right side.It is inside a hole big enough to get your hand in but it is in tight quarters. This holder I believe turns to the right. I used a flashlight to see where it was.
If you mean it stays on and does not blink then check the other turn signal bulbs on the right side front/back. If it blinks but does not turn off when you make a turn then the problem is in the steering column canceler.
right next to the oil pan, below car
94 buick lesabre was right at the change over( obd1 to obd2) some have an obd2 connection with an obd1 computer. this can only be read by buick garages. go to auto zone or checker auto and they can tell you.
The 1997 Buick LeSabre mass airflow sensor is located on the outside of the air intake housing. The sensor can be found on the right hand side of the air intake housing.