Check the bulb or bulbs. If not the problem, check to see if they have a good ground.
See sources and related links below for 1993 Dodge Shadow tail light, brake light and turn signal light bulb part numbers.
The Dodge Shadow stopped production in 1994
check the light bulb same double element bulb for both lights
Under the dash, on the brake pedal arm mounting bracket.
Assuming the signal lights still work, no. But a bad brake light switch or a blown brake light fuse could.
More than likely you have a burnt out bulb at the front signal light, rear signal light, or brake light on the right side.
tail/stop/turn signal bulb # 3057 park/turn signal bulb # 3157NA
Probably the turn signal flasher
If you have the same bulb for brake and signal, brake light power needs to be interrupted by the signal lights, The brake circuit has to go through the signal light switch so the problem could be there.
it means that you have a bulb out somewhere on your truck.... IE backup light, brake light, turn signal, running light.. etc etc..
I should be just above the brake pedal where the shaft of the pedal pushes up against the switch. It should be easy to adjust or replace
Bulb is out.