1994 will have separate rear turn signal bulbs.
Brake and taillights share a bulb.
If you have a trailer light connection I would start there, follow the wires to the splice point.
Light Green/orange stripe wire will be Drivers side turn signal wire.
Orange/light blue stripe will be Passenger side turn signal.
Use a test light/volt meter to see if you have power there when that turn signal is on.
If so try a replacement bulb, flashing turn indicator doesn't mean all bulbs are "good", as described below dash and front turn signal bulbs are on a different circuit than rear turn bulbs.
If no power is there, then those two wires run to a connector on the steering column, where it plugs into the Multi-function switch(turn signal stalk)
The rear turn signals operate on a separate switch inside this switch.
The dash indicator and front turn signals are both on another switch inside this switch.
So problem could be in the multi-function switch.