93 Roadmaster odometer

[Guest]

I've recently bought a used 1993 Roadmaster Estate wagon. The odometer does not work all the time. One shop I went to said it is electrical and the entire dash has to be disassembled. Another shop says it is mechanical and isn't that big a deal. Who's right? Perhaps neither? Any help appreciated.

[NTX5467]

Most all of the GM instrument clusters by that time were electronic. The easiest way to determine which it is is to look on the left hand side of the transmission tailshaft housing. If a normal speedometer cable casing is attached, it's the older style "analog" setup. If it has wires from a speed sensor instead, it will be "electronic".

In the electronic clusters, the odometer is run by an electrical stepper motor. The motor could have failed or the wiring that runs it could have a problem. If the speed sensor at the trans had failed, it would cause the speed signal to the ECM to not happen and would set a code in the computer and turn on the Check Engine Light.

These stepper motors might be available in the specialized AC-Delco service part of things (a completely separate part from normal Delco replacement parts at the auto supplies or dealerships) so they could be available to a speedo shop that does those things. I suspect there might still be some in the larger metro areas, though.

Typically, there are no "user serviceable" items in those clusters. At the dealership level, we would send them to an authorized AC-Delco service center for exchange. If there's one near you, you might take the vehicle to them or ship the cluster to them. Usually, their turn-around time is pretty quick.

You might contact your local Buick dealer to see where they would send it and what pricing might apply (for the exchange cluster and R&R labor).

NTX5467