880 and 881 Bulbs Explained: The H27W Fog and Spot Bulb, Its Base, and How to Replace It
An 880 bulb is a 27-watt single-filament capless bulb on a PG13 base, used for fog lamps, spot lamps, and daytime running lamps. The 880 is an H27W/1 bulb, and its close relative the 881 is an H27W/2 bulb on a PGJ13 base, so the two share the 27-watt filament but differ in base. The […]
H6W Bulbs Explained: The 434 BAX9s Sidelight Bulb, Its Offset-Pin Base, and How to Replace It
An H6W bulb is a 6-watt single-filament bulb on a BAX9s offset-pin bayonet base, used for sidelights, parking lamps, and interior lamps. The H6W carries the UK trade codes 433 and 434, so a box marked 434 holds the same bulb as a box marked H6W. The bulb twists into a small 9-millimetre bayonet holder […]
W16W Bulbs Explained: The 921 Capless Reversing Bulb, Its Base, and How to Replace It
A W16W bulb is a 16-watt single-filament capless bulb on a W2.1×9.5d wedge base, used for reversing lamps, high-level brake lamps, and bright marker lamps. The W16W carries the UK and international trade codes 921 and 955, so a box marked 921 holds the same bulb as a box marked W16W. The bulb pushes into […]
R5W Bulbs Explained: The 207 BA15s Sidelight Bulb, Its Base, and How to Replace It
An R5W bulb is a 5-watt single-filament bulb on a large single-contact BA15s bayonet base, used for sidelights, tail lights, number plate lamps, and interior lamps. The R5W carries the UK trade code 207, so a box marked 207 holds the same bulb as a box marked R5W. The bulb twists into a standard 15-millimetre […]
Halogen Bulb Lifespan: What Affects It and How to Maximise It
A halogen bulb lasts between 500 and 1,000 hours of use in normal conditions. The figure is the rated life set by the manufacturer, and it assumes a stable voltage, clean handling, and little vibration. On a tractor or a work lamp, none of those conditions hold, so a halogen bulb on a farm vehicle […]
Why Do My Tractor Bulbs Keep Blowing: Common Causes and Fixes
A tractor bulb that keeps blowing has one of five root causes: charging-system over-voltage, vibration, wiring or earth faults, fitting damage (skin oils on a quartz envelope or a knock during handling), or the wrong bulb specification fitted in the first place. The bulb itself is almost never at fault on a single replacement, but […]
H4 vs H7 Bulbs: Differences, Uses, and Which One You Need
H4 and H7 bulbs are the two most common halogen headlamp bulbs fitted to tractors, telehandlers, and farm vehicles in the UK. The H4 bulb is a dual-filament unit that provides both dipped and main beam from a single bulb. The H7 bulb is a single-filament unit that handles one beam function only. The two […]
Vehicle Bulb Types Explained: A Complete Reference by Code
A vehicle bulb is identified by an alphanumeric code that fixes its base shape, filament arrangement, wattage and rated voltage. The four most common families of code on UK road and agricultural vehicles are halogen headlamp bulbs (H-series), bayonet bulbs (P-series), capless wedge bulbs (W-series and T-series), and festoon bulbs (C-series). Each code has a […]