Many different Scalextric cars have been fitted with lights, from the early E1 to E5 range of Scalextric cars to the current range of Scalextric cars. In the early days small bulbs were used and as time passed these were replaced with LEDs.
The most common problem with bulbs is the traditional problem of the bulb filament breaking, known as a blown bulb. The answer is to fit a replacement Scalextric bulb. There are only a few different bulbs used and they are easily identified. Nowadays there are some more options where high brightness bulbs can be used that give more light as slower car speeds.
LEDs were first used as rear lights, brake lights and for the turbo flash on the Formula 1 cars. With Scalextric cars like the Porsche 962, Ferrari F40 and several others of the period, the LED rear light actually use the headlamp bulb in the circuit. This means that when the headlight bulb(s) blow none of the lights work, and , no, we do not know why Scalextric did this. Replacing the headlamp bulbs should restore full function to the lights.
With the more modern range of Scalextric cars with LED lights all round, if the lights don’t work the chances are the polarity is wrong, which can happen easily.
Another great insight from Scalextric Car Restorations