H.I.D (High Intensity Discharge) Ballasts

H.I.D Ballasts are becoming more popular and have been requested on a number of occasions via 360.

As a result, this category has been looked in to further and 26 NTR parts to range from Valeo, Hella and Magneti Marelli have been added to stock and are now available from Sheffield.

Ballast Function
Ballasts are required to trigger and operate H.I.D Xenon lamps fitted to a 12-volt electrical system, to trigger the lamp, the ballast produces a high voltage of approximately 23,000 volts along with adjusting the current flow through the lamp to 2.5A and the maximum power to 70 watts.

After triggering, during operation, the ballast adjusts the lamp power of 35+/-1 watt, the lamp voltage is then reduced to between 67 and 112 volts. To ensure good operating conditions the ballast works only when it receives 9 to 16-volt supply voltage.

To prevent any damage to the ballast, the ballast switches off if the lamp is not operating after attempting to trigger it 4 times. Additionally, a safety device, like a trip switch in household electrics, is installed.

Effects of failure
A faulty ballast causes a total loss of the headlamp operation.

Causes for failure can be the following:

  •  Faulty supply voltage
  •  Faulty ground/earth
  •  Faulty xenon ballast
  •  Faulty xenon lamp
  •  Internal short circuit

Diagnostics
Consider the following check steps before replacing a H.I.D ballast:

  •  Check for triggering attempts of the ballast after switching on the headlamps, if triggering attempts fail, the xenon lamp should be renewed.
  •  If no trigger attempts are carried out, the fuse should be checked.
  •  If the fuse is ok check for voltage and ground/earth at the ballast, the minimum voltage must be 9 V and maximum 16 V.
  •  If the voltage, ground and the xenon lamp are ok, a faulty ballast is the cause of the failure.

Important note
During the supply voltage check, the ballast must be securely connected to both lamp and supply connector. When working on the xenon lamp the ballast must be disconnected, to prevent any electrical shocks.