Halogen Lamp
From Sinspeed
Halogen Lamps are the conventional source for lighting automotive headlights. This means that the majority of vehicles both old & new come with Halogen lamps as standard, however, Xenon Lamps are becoming more available as an upgrade and as standard on some newer vehicles. A halogen lamp is an incandescent lamp with a filament and a small amount of Halogen gas, such as Iodine or Bromine. Halogen lamps work well, however, they require a lot of power to operate and have a shorter lifespan than newer technologies such as Xenon Lamps. Halogen bulbs are available in all regular sizes for example: H1, H3, H4, H4 (Hi-Lo), H7, H9 & H11.
Halogen lamps are readily available from 100's of stores nationwide such as Halfords, Euro Car Parts, Partco and Sinspeed. They're very cheap to buy and easy to fit - most commonly plug & play. In order to operate, we need to have a closed circuit, this means the filament from one end to the other end inside the bulb should be in clear contact. This allows for electricity to flow through it. When a halogen bulb is blown, it will stain the glass partially black or you will be able to visibly see that the filament is broken and the circuit is open - not allowing electricity to flow freely from one end to the other end.
Some newer vehicles are fitted with Canbus Wiring Systems. A Canbus wiring system is put in place to offer consumers a bulb warning error if their vehicle has a blown Halogen bulb. It does this by passing a very small current through the headlight wiring loom, right the way through the filament of the Halogen Bulb. The current should leave out from one side of the Headlight ECU (Electronic Control unit), through the wiring loom and through the Halogen bulb.. right across the filament, back out the other side of the bulb and back through the wiring loom all the way back to the Headlight ECU. If the circuit is closed and there is no interruption to this current then the handshake process will be completed and the on-board headlight ECU system will not report any errors. This means that current can freely pass through the bulb, therefore meaning that the bulb is in perfect working order. If however, the current is not able to meet at the other end of the ECU and close the circuit to perform a completed handshake, then the headlight ECU will report a bulb failure error. This error can come in the form of a single bulb warning image appearing on the dashboard or a message on larger digital dashboards stating "Bulb Out" or "Bulb Failure".
