instrument cluster

[tech1gmc]

I have a '87 turbo t, and the boost gauge does not work. Is it the instrument cluster, or guage?

 

[GNeric]

Could be the MAP sensor on the passenger fender near the antenna mount. Make sure the vacuum line is not split and that it is hooked up. Line and wires. If you have the digital dash, there will be a round piece with a 2 wire connector and a vacuum line.