'96 Volvo 850 GLT Speedometer/Odometer

I’ve had my Volvo for about 3 and a half years. In the last 6 months or so, when I turn on the car, the speedometer will not work. Every time that it does work (about 1 in 5 times) it will eventually stop working. While I’m driving the odometer won’t measure my mileage and the cruise control doesn’t work either. The ABS light has been on since I got the car, but the previous owner told me that it wasn’t a real problem with the brakes, the light just cost $900 to turn off. The service light also comes on intermittently, but will cut off randomly as well. The check bulbs light also comes on intermittently, but I haven’t noticed any pattern with any of the lights coming on. Thanks, Steven.