The vehicle speed sensor (VSS) on a 1987 Chevy Blazer is located in the
transmission. There's no single definitive location as it depends on the specific transmission type (automatic or manual). However, it's generally found on the
output shaft of the transmission where the driveshaft connects. It's a relatively small sensor.
You'll likely need to get under the vehicle to find it. Be sure to consult a repair manual specific to your Blazer's year and transmission type for the exact location and removal instructions. A diagram showing the transmission components will be very helpful.
