Hey everyone, I recently bought a 1990 V6 Camaro RS. The speedometer in the car doesn't seem to work right but all the other gauges do. It seems that the speedometer reads 0mph most of the time or jumps around but if I'm going up a hill or giving the car gas it will read correctly. I have already replaced the speed sensor with a new one but it didn't work at all so i put the original back in. I have also taken out the instrument panel to check for loose or dirty connections but we didn't see any. Does anyone have any suggestions? We're out of ideas, thanks for your help.

 

I've found with a sporadically working speedo that the wiring connections were the main source of problems. The connection at the back of the cluster and the connection at the vss. Vibration, bump in the road, cornering or change of angle causing the speedo to work, look for the circuit that goes open & complete.