1987 dash illumination problem

The dashboard illumination dims when the vehicle's lights are activated, which is normal during daylight. The dashboard assembly was removed and sent to a local Corvette specialist for repair. Upon follow-up with the dealer, it was reported that the repair facility identified several issues, which were addressed, and the cluster was tested to function correctly. The dealer suggested replacing the headlight switch, as it was noted that the center stack gauge switch lights were also non-functional. A ground wire jumper was created and connected to the #1 position in each dash cluster connector, with the other end connected directly to the battery ground. However, the issue persisted, with the dashboard still dimming when the lights were turned on. The light sensor appears to be functioning properly; the dashboard is bright with the lights off, and it dims in response to blocking light in front of the sensor.

The described issue involves a complex interaction between the dashboard illumination system, the light sensor, and the headlight switch. The dashboard illumination typically relies on a combination of power and ground connections to function correctly. When the lights are turned on, the dashboard should remain illuminated, but in this case, it dims, indicating a potential fault in the circuit.

The headlight switch serves as a critical component in controlling the power to the dashboard lights. If the switch is faulty, it may not provide the necessary voltage to keep the lights illuminated. A thorough inspection of the headlight switch should include checking for continuity and ensuring that the switch is properly connected to the dashboard assembly.

The creation of a ground wire jumper suggests that there may be an issue with the ground connections within the dashboard cluster. A reliable ground is essential for the proper operation of the illumination system. If the ground connection is compromised, it can lead to erratic behavior, such as dimming when the lights are activated. It is advisable to inspect all ground points associated with the dashboard illumination circuit to ensure they are clean and securely connected.

The light sensor's behavior indicates that it is functioning as intended, adjusting the brightness of the dashboard based on ambient light levels. However, if the sensor is not integrated correctly with the dashboard illumination system, it may not compensate appropriately when the vehicle's lights are activated. Testing the sensor's output voltage under different lighting conditions can help confirm its operational status.

In conclusion, to resolve the issue of dashboard illumination dimming when the lights are turned on, a systematic approach is required. This includes verifying the functionality of the headlight switch, ensuring proper ground connections, and confirming the light sensor's integration with the dashboard illumination system. Each component should be examined thoroughly to identify any faults that may be contributing to the observed behavior.Dash illumination goes dark when I turn on the lights (normal in daylight). Took the dash out and ended up sending it out for repair via local Corvette specialist dealer. * Checked back with local Corvette dealer. He checked with place that did work on cluster. They said they found a few problems, fixed and tested cluster and it worked correctly. Suggested I replace the headlight switch, based on fact that they had me check to see if the lights for the centerstack (guage switch lights) did not work either. * I then made up a ground wire jumper and connected that to the #1 position in each dash cluster connector and ran ground directly to the battery ground.

Same problem - dash goes dark when lights turned on. * The light sensor "seems to work" correctly. With lights off, dash is bright. If I block light in front of sensor, dash dims according to amount of light available. 🔗 External reference