Editing Z31/DigitalDashRepair php (section)

=== Digital Speedometer Always Reads "0" ===

If your digital dash shows '''“0”''' at all times, the issue is usually a failed
'''speed sensor''' or a broken '''speedometer cable'''.
The speed sensor is sealed with epoxy, but over time the epoxy cracks, allowing water or salt to
damage the internals.

![https://dev.z31library.com/xenonzcar_archive/z31/images/Digital%20Dash/spdsensrt.jpg Z31 Digital Speed Sensor]

==== Step 1: Test the Speedometer Cable ====

* Locate the speed sensor on the fender well near the battery. It has the speedometer cable and four wires (red, green, black, yellow).
* Unscrew the locking ring and remove the cable from the speed sensor. Watch for the black plastic alignment ring—do not lose it.
* Prop the cable so you can see the square end. Put the car in 5th gear and roll it forward/backward 3–4 feet.
* If the cable rotates about half a turn, the cable is good. If it doesn't move, the cable is broken.

==== Step 2: Bench Test the Speed Sensor ====

You’ll need: insulated alligator clips, a multimeter (analog preferred), and a 5–6V DC source.
'''Never apply 12V directly!''' If using the car battery, put a 750Ω resistor in series.

'''Black:'''Ground'''Red:'''+12VDC'''Yellow:'''Signal

Connect power to the black (ground) and red (+DC) wires. Connect the multimeter to black and yellow, set to 10K–100KΩ. Slowly turn the sensor shaft:

* If working, the analog needle will swing or digital resistance will vary from ~200Ω to infinity.
* If you see no movement, the sensor is bad and must be replaced.

==== If All this Fails... ====

If these steps fail to correct your issue and the sensor and cable both test good, Then the issue is internal to the cluster. Usually the other gauges will still be lit up but the readings will not be correct at all. The Voltmeter will usually read 16 (Max) and the other gauges will read near 0.

A Lot of times this can be repaired here at XenonZcar as the issue is caused by one of the Ceramic IC boards internal to the Cluster. The solder cracks off and the ceramic surface and the only fix is to replace it with a updated version as solder will not stick back to the ceramic.