The most likely cause is the turn signal flasher.
The 2003 Chevy S 10 pickup truck turn signal flasher relay switch can be found beneath the drivers side dashboard. The turn signal flasher relay switch will be between the gas pedal and the brake pedal.
Where do you find the four way flasher in a Chevrolet avalanche (2003)
how do you fix turn signal
The turn signal/hazard flasher is integrated into the flasher switch. A very common failure on these cars.
Above the radio there is a button with red triangles on it. That is where the turn signal flasher is. You have to take the dash off to get to it.
Most likely a bad turn signal flasher
The turn signal flasher is located in the same assembly as the hazard button the dashboard just above the stereo. You need to remove the trim pieces from the dashboard in order to access the flasher assembly.
It is part of the hazard push button switch.
The most probable answer is that you have a bad flasher.
The turn signal flasher relay on a 2003 jeep Liberty is in the fuse box that is below the glove compartment. Look for a large box type plug in with three prongs inside the fuse box.
Module part of Hazard warning switch