High Intensity Discharge Headlamps

High Intensity Discharge Headlamps

The high intensity discharge headlamps are supplied B+ voltage and ground, the same as normal halogen low beam lamps. The low beam system is different from there forward. The ballast module is mounted to the bottom of the headlamp unit. The ballast module has internal circuit protection to prevent module damage in case of an open or shorted circuit. The module has overcharge and undercharge circuit protection. If either is sensed, the module will not illuminate the headlamps for that key cycle or until the fault is corrected. Recycle the ignition and headlamp switch if both headlamps do not illuminate. Before determining the headlamp assembly is faulty, test the connector at the headlamp and test if there is voltage coming from the totally integrated power module pin providing the power to the respective headlamp. If the module senses a short or open circuit condition, it will not operate the lamp/igniter.


The headlamp unit must be removed to perform these tests.

- Inspect lamp for a burned out lamp. If lamp is burned out it will appear black or smoky, similar to a normal halogen bulb.

- Test for B+ battery voltage at the connector going into the ballast module. If B+ voltage and a good ground are not present, refer to for circuit and connector locations to find short or open circuit.

- Plug in a known good ballast module and test for lamp operation. If lamp lights, replace ballast module. If lamp still fails to light, replace igniter assembly.