1999 Plymouth Voyager Single lights

The lights will flash at night when the car is off and no key in it? As far as the issue, are you certain you got the correct bulbs. Some bulbs are single element bulbs and will fit into the socket of a dual element. Also, have you checked the flasher? When you turn the signals on, do the indicator lights inside light up?

Right now the indicator light don't show on the dash, I purchased the bulbs that it said was for my vehicle. Yes I checked the flasher and it seemed to be fine

All fuses are good? If they are and you are getting power to the switch, the flasher is good, and the bulbs are good, I would have to suspect the switch itself or for some reason you have totally lost the ground for the circuit.