autobeef is full of people with this problem. there is a special warranty for fixing it.http://www.carcomplaints.com/Chevrolet/Silverado/2004/electrical/index.shtml
If you are over the 70K miles and not able to take advantage of the recall
just go to www.speedometergaugerepair.com they fixed mine for 140
rpm and speedometer gauges not working 1995 Chevy silverado 2wd
If the speedometer is not working but the odometer is, I would suspect the dash cluster is at fault. If both speedometer and odometer are not working I would suspect the speed sensor on the transmission is at fault.
It will need to be recalibrated at a shop that specializes in speedometer repair.
You can only adjust the speedometer with an ERA - Electronic Ratio Adaptor or possibly the Dealer, because the Speedometer is electronic.
It does not have 1. It is all computer controlled.
If the speedometer is not working it probably needs a new speedometer cable. If the speedometer is actually broken either take it to as speedometer repair shop or replace it.
I have a 1990 and the speedometer kept dropping out to zero, which caused errors on the main computer and also the RWAL computer. Removing the speedometer gauge from the panel (it pulls straight after undoing the screws), cleaning the contacts, bending the contacts in a bit so they were touching the pins better, and re-inserting the speedometer fixed the issue. Took half an hour and $0.00. For that year, it's an easy fix anybody can do, Chevy designed a great panel that year.
You can't you have to replace the whole dashboard instrument cluster assy.
Buy a new Speedometer cluster. The external Temp gauge is extremely rare
PROBABLY one of the little tiny itty bitty gears has stripped
NO.
Check your fuses.