Chevrolet Repair: speedometer troubles, chevy lumina, lumina car

Question
hi i have a 91 chevy lumina car with a 3.1 liter motor auto tranny. the speedometer when i first bought it would kick on randomly while driving . i changed the speedometer sensor on the transmission and bought a new cluster still nothing works. i have checked all the fuses. are there any multimeter measurements i can make? or what else should i do?

Answer
Hi Adam... you need to find the open in the speedo circut...check the connections to be sure that they are clean and making contact. if you can hook up scan tool drive the car and see if you are getting a speed reading on the scan tool... your problem my be in the computer...hope this helps