You should still have a mechanical speedometer. Near the back of your transmission is a cable going into the tailshaft. Unbolt the retaining clip and slide the gear out of the tranny. Inspect it for broken/missing teeth. You can obtain a replacement at any parts store, just know your engine/trans type and your rear end gear ratio. It could also be a bad ground at the speedometer itself.
There are several possibilities why the speedometer is not working. The VSS, vehicle speed sensor may have failed or become unplugged. The speedometer may have failed, or the ECM, engine control module, may have failed or there could also be wiring issues.
The 1987 Celebrity uses an electronic speedometer. There is a VSS(vehicle speed sensor) on the trans-axle that could have failed. The speedometer itself may have failed, the ECM (engine control module "computer") may have failed or there could be wiring issues.
Possible failed rear axle speed sensor. This truck does not use a cable, the speed signal comes from the ABS.
The 1987 Chevy Celebrity uses an electronic speedometer, there is no speedometer cable. Assuming your speedometer has failed here are some possible causes: The VSS. vehicle speed sensor, may have failed. The speedometer may have failed. The ECM, engine control module aka computer, may have failed. There may be wiring issues such as unplugged, dirty connections, broken wires, etc.
Speed sensor
Fuses, broken wire, failed PCM, failed gauge.
There is no speedometer cable. MPH is calibrated using a speed sensor. If your speedometer is not working, you have a bad speed sensor module.
The speed sensor is located in the speedometer assembly, at the back of where the speedometer needle connects.
The vehicle speed sensor which is an integral part of the speedometer
Possible reasons your speedometer not working: 1. The vehicle speed sensor has failed. 2. The speedometer itself has failed. 3. There is a failure in the wiring or connectors. 4. The engine control module has failed. I don't know what you mean by "fuel mix", please clarify.
controls speedometer
the speed sensor, trans. sensor , or the speedometer cable