Hello, please advise me: my Chevy silverado 1500 speedometer needle stays at 60 mph when the vehicle is off. If I drive at 20 mph it shows 80 mph. Ever so often it goes back to zero and works properly. Can anyone tell me how to fix this issue. Thanks in advance.

 

What is the year of your Silverado? Between 03 and 06 there was a recall on the instrument cluster because the stepper motors for the gauges were prone to failure. If your truck falls in that group you can try to see if you are in the recall. If you can solder you can fix it yourself. You should also replace all 6 stepper motors while you are at it.