The MGA's original lighting was designed to the standards of the 1950s and early 1960s, and even in good condition it falls well short of modern expectations for night-time visibility. This category covers lighting upgrades for the MGA, from improved bulbs and halogen conversions to LED options and supporting relay kits, allowing owners to improve safety and visibility while retaining the car's period appearance.
Positive Earth and Polarity
All MGAs were built with positive earth electrical systems, and this is critical when selecting lighting upgrades. Conventional filament bulbs are not polarity-sensitive, but many LED units are, and will only work when wired to the correct polarity. On a positive earth car, an LED designed for negative earth will not illuminate until its connections are reversed or a polarity-correct unit is chosen. Cars converted to negative earth must be matched accordingly.
Establishing the car's polarity before ordering prevents the most frequent fitting problem.
Headlamp Improvements
The MGA's sealed-beam and pre-focus headlamp arrangements can be significantly improved. Halogen bulb conversions offer a marked increase in light output over the original tungsten units while fitting within the existing headlamp shells, preserving the car's external appearance. LED headlamp options provide further gains in brightness and reduced current draw, an advantage on a car whose charging system was never designed for heavy electrical loads.
Relays for Headlamp Circuits
A headlamp relay kit is one of the most effective upgrades available. The MGA's original wiring routes full headlamp current through the dash switch and a long wiring run, causing voltage drop that dims the lights. A relay kit allows the lights to draw current directly from the battery via a short, heavy feed, with the switch operating only the relay. This restores full voltage at the bulbs, brightening the lights and reducing strain on the original switch and loom.
Side, Tail and Indicator Lighting
Improvements extend beyond the headlamps. Brighter or LED side, tail, brake and indicator bulbs improve the car's visibility to other road users.
Where LED units are fitted to indicator circuits, the reduced current draw can affect flasher operation, and an electronic or adjusted flasher unit may be required to maintain the correct flash rate. As with all electrical components, polarity must match the car's earth configuration.
Appearance and Reversibility
Lighting upgrades for the MGA are generally chosen to improve performance without altering the car's looks, and most can be carried out without permanent modification. This allows owners to enjoy safer modern lighting while retaining the ability to return the car to original specification, an important consideration for cars that may later be restored to concours standard.