How to Replace the Odometer Light in a BMW Z3 Instrument Cluster
1. Disconnect the negative terminal on the battery. Ensure that you have the code for your radio if it is the OEM stereo, since disconnecting the battery resets it.
2. Remove the Torx screws that hold the instrument cluster to the dash pod with a T20 Torx bit and a ratchet.
3. Protect the plastic on the gauge panel with a piece of flannel. Also lay a heavy towel on the steering column to offer more protection.
4. Slide a very thin tool (feeler gauge, thin spatula, etc.) between the cluster and the gauge pod on the edge near the center of the car. Very gently pry the cluster out far enough so that you can access the wires on the back of it.
5. Disconnect the three electrical connectors that go to the back of the cluster. The connectors are released by pressing the tabs down where they connect and pulling the wires out. Move the cluster to your workbench and lay it on a soft towel.
6. Replace the two odometer bulbs by turning and pulling them out of the instrument cluster and installing the new ones. Use a small screwdriver to help twist in the new bulbs. The odometer bulbs are beige. All of the other bulbs are black.
7. Place the instrument cluster back in the dash pod and connect the three electrical connectors. Carefully slide the cluster back into place and tighten the two Torx bits. Enter the radio code if needed and reset the clock.