Simple Checks (Do these first):
* Blown Fuse: This is the most common cause. Check your owner's manual for the fuse box location and diagram. The fuse for the instrument panel lights is usually clearly labeled. Replace any blown fuses with the correct amperage.
* Dimmer Switch: Your Cherokee likely has a dimmer switch that controls the brightness of the dashboard lights. Make sure it's not turned all the way down or malfunctioning. Try adjusting it.
* Loose Bulbs: The individual bulbs for the various dashboard lights could have become loose or burned out. Access to these bulbs varies depending on the model year and trim level, often requiring removal of the instrument cluster bezel. Inspect and replace any burnt-out bulbs.
* Bad Ground Connection: A poor ground connection can interrupt the electrical circuit. Check the ground wires connected to the instrument cluster and the fuse box. Clean any corrosion and ensure tight connections.
More Involved Issues (Require more troubleshooting):
* Instrument Cluster Failure: The instrument cluster itself could be faulty. This is more likely if *all* dashboard lights are out, not just some. Repair or replacement of the instrument cluster is usually costly.
* Wiring Problems: Damaged or corroded wiring between the fuse box, dimmer switch, and instrument cluster could interrupt the circuit. This would require tracing the wiring to find the problem.
* Faulty Switch or Relay: Although less likely, a faulty switch (other than the dimmer) or relay could be interrupting the power to the instrument panel lights. Identifying the correct switch or relay will require more investigation.
* Power Supply Issue: A problem with the vehicle's electrical system, such as a failing alternator or battery, could also affect the dashboard lights. A low voltage supply may not be enough to power the lights.
Troubleshooting Steps:
1. Start with the simple checks: Fuses, dimmer switch, and bulb inspection.
2. Check for voltage: Use a multimeter to check for voltage at the fuse, the dimmer switch, and the instrument cluster connector. This helps pinpoint where the circuit is broken.
3. Consult a wiring diagram: A wiring diagram specific to your 1990 Jeep Cherokee will be invaluable in tracing the circuit and identifying potential problems. You can often find these diagrams online or in a repair manual.
4. Professional Help: If you're not comfortable with electrical troubleshooting, it's best to take your Jeep to a qualified mechanic.
Remember safety first. Disconnect the battery negative terminal before working on any electrical components in your vehicle.
