your car doesn't have a speedometer cable it has a speed sensor that may be causing that too happen to it,have the computer scanned and see if you don't get trouble code for a bad speed sensor ,and if that's not it you may have a bad dash unit in it,those was real popular for causing problems like this,and on the flashers try removing the fuse and then replacing it see if that helps it,if not replace the flasher unit on it,and if the still do it, you,ll have to replace the switch that goes in the steering column,good luck.
