Turn Signals

2003 Grande Caravan. The left turn signal just decided to come on while the van is running and does not turn off untill the van is turned off. When I use the signal switch to turn right or left the right side blinker comes on. When the switch is in the center/off position the left side turn signal stays on all the time. I have diconnected the turn signal switch inside the steering column and the left blinker continued as it had before, but I can no longer turn on the right side blinker as before. I have removed the left front and then the left rear blinker bulbs one at a time. Same result with both of them: The blinker light and the display inside both blink very rapidly. When the lights are both back in the system they blink at the normal rate, they just never turn off unless the van is off. The Hazard light switch still turns on both blinkers, but when I turn them off, once again the left blinker stays active. I checked the fuse for the signals, when removed this turned off the malfunctioning blinker, it alson turned of the dash display lights. When the fuse was replaced, the left blinker was back at it. Any help would be greatly appreciated.