Loose or disconnected wire: Check that the wires connected to the alternator are secure and properly connected. A loose or disconnected wire could disrupt the power supply to the instrument cluster, causing the lights to go out.
Damaged wiring: The wiring harness that connects the alternator to the instrument cluster may have been damaged during the alternator replacement. Inspect the wiring for any signs of damage such as cuts, breaks, or exposed wires.
Faulty instrument cluster: The instrument cluster itself could be faulty, which could explain why the lights are not coming on. To diagnose this, try swapping the instrument cluster with a known working one or have it tested by a qualified technician.
Electrical issue: There may be an underlying electrical problem in the vehicle's electrical system, such as a blown fuse or a faulty electrical component. Check the vehicle's fuse box to see if any fuses related to the instrument cluster or the alternator have blown.
If you are not comfortable troubleshooting electrical issues, it is best to have the vehicle inspected by a qualified mechanic or electrician to diagnose and fix the problem.
