There could be a possible fuse blown some where?...check the fuses for marking lights You may also want to look for the turn signal relay, try putting on your 4-way hazard flashers and see if those work, if they do you can here the clicking noise of the relay, might be under your dash. In my car it was underneath the dash directly in line with the steering column, above the brake pedal.
Bulbs or turn signal flasher, maybe even the switch.
Turn signal flasher may be defective
Blown fuse/? blown bulbs /?bad flasher.
Remove the entire headlight assembly to gain access to the bulbs.
The socket size for the trunk tail light on a 2001 Buick LeSabre is 7mm. Bulbs can be purchased at most local automotive repair stores.
ensure all bulbs on bumpers are good
If you can not remove fasteners on outside, you may need to cut a section out of the inside of trunk to get your hand by the bulbs.
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.
Check for burnt out bulbs and could be a bad flasher as well.
The side marker bulbs on a 2002 Buick LeSabre are replaced by removing the retaining screws and disconnecting the wiring harness. The old bulb can then be removed and a new bulb put in its place.
When replacing the rear turn signal on a 1999 Acura Integra open the trunk. Locate the rear turn signal housings and find the bulbs. Remove and replace the bulbs.
Bulbs cannot be replaced. Entire control module must be replaced.