280ZX Headlight Problems
A common problem on 280ZX models is one or both headlights becoming noticeably dim over time. This is often caused by increased resistance in the wiring, corroded connectors, or weak grounds. Since the headlight current passes through the combination switch, wear and tear on the contacts can also lead to voltage drop and reduced brightness.
Fixes can include cleaning and tightening all relevant connections, verifying the ground points, and in some cases, installing a dedicated headlight relay harness to reduce the load on the original wiring and switch. A relay upgrade delivers full battery voltage directly to the headlights, significantly improving brightness and reliability.
Common 280ZX Headlight Dim/Fault Issue
The usual culprit for dim or failed headlights on the 280ZX (S130) is the backside of the combination switch where the headlight harness plugs in.
This switch has a known weak point — a single pin that often fails due to electrical overload. Over time, the pin heats up, develops carbon buildup, and increases resistance in the circuit. This resistance can cause the headlamp to become dim or fail completely.
The carbon acts like an insulator, blocking proper current flow to the lights. Cleaning or replacing the affected pin can restore headlight performance, but many owners choose to install a headlight relay harness to prevent recurrence.
Above: Example of carbon buildup on the combination switch connector pin, causing increased resistance and dim headlight output.