The MGB's lighting evolved considerably across eighteen years of production, reflecting both the technology available and the regulatory requirements of the markets the car was sold into. Early cars used 7-inch sealed beam headlamps in chrome bezels, which remained standard until 1976 when H4 halogen units became standard fitment, a significant improvement in beam quality and lamp life. The MGB GT V8 uses the same conventional lighting layout and shares its system with the contemporary four-cylinder MGB GT in most respects, with V8 differences concentrated in the bumper-area lamp installations and mounting details.
Headlamps
Original sealed-beam units fail completely when the filament breaks, with no possibility of bulb replacement, whereas modern halogen sealed-beam units offer significantly brighter output and bulb-replaceable units offer further upgrade flexibility. Halogen conversion kits are available for both chrome and rubber bumper cars, and high-power bulbs are available for cars fitted with relay-based headlamp wiring. Running high-power bulbs through the standard headlight switch without a relay will cause premature switch failure, so relay conversion is strongly advised before fitting upgraded bulbs. Headlamp aim is set via adjusting screws at the headlamp bowl mounting.
Side & Indicator Lamps
The hazard warning switch is the first component to check when indicators fail, as the indicator circuit runs through the hazard switch and a failing switch will disable the indicators entirely. A hazard warning light and relay kit is available for pre-1974 cars not originally fitted with the system. Front side lamps and indicators differ in their installation between chrome bumper and rubber bumper specifications. Bulb specifications, lens colours, and lamp dimensions match the factory specification with original-pattern replacements available.
Rear Lighting
Sidelamp and rear lamp assemblies differ between GHN3/GHD3 and later GHN5/GHD5 cars, and between home market and export lens specifications. Rear lamp clusters combine tail lamps, brake lights, indicators, and reverse lights, with reverse lights operating from a switch on the gearbox that closes when reverse gear is selected. The rear lighting clusters differ between chrome bumper and rubber bumper cars, reflecting the rear-end body and bumper differences. Number plate lamp assemblies changed at several points and are available in the correct specification for each period.
Interior & Auxiliary Lamps
Interior lighting components cover boot and tailgate lamps, console and courtesy lamps, map lights, and door warning lights. Period driving and fog lamps are available in Lucas, Wipac, and Cibie styles with wiring kits for clean installation.