My speedometer is not working is it a cable? a fuse? a relay? i need to fix 1985 buick lesabre 307 v8 4 barrel rocker

Yes it is the cable type. The instrument cluster must first be removed. Depress the retaining clip on the back of the cluster to release the speedometer cable. Once the end of the speedometer drive cable is exposed, grip the inner cable with pliers and draw it out of the housing. Installation is the reverse of removal, but lubricate the entire cable. Use special speedometer cable lubricant, Not oil, for this purpose. Insert the cable into the housing using a twisting movement until the lower end is felt to engage with the pinion gear at the transmission. You can also check the Pinion Gear at the transmission, That is where the speedometer cable connects to the transmission. Some times these small nylon gears will strip out caused from no lubrication in the speedometer cable housing. If the above does not solve your problem you may need to change out the cluster itself to obtain a good working speedometer head. Good Luck and Happy New Year. From Ernie @ RedDeer, Alberta, Canada.

I had the same problem. I disconnected the negative battery cable at the battery under the rear seat. After one minute reconnect the cable. This will reboot the computer and cure the problem.(2004 buick lesabre speedometer)