have a 1990 blazer and the tach and speedometer is not working. Both needles move when I start the truck but then stop. I changed the vss that screws into the transfer case and still nothing. Any ideas? Also on the back of the instrument cluster the plastic with the electronic strips are not against the back of the panel on one side. Woul that matter?

 

You know, I've been having some similar problems. Mine actually will work sometimes though. I'd really like to know if you find anything out that turns out useful!