Does Anyone Know Why

[SMJ7]

I have a 1993 LS400 and My rear light bulbs have a double filament type bulb fitted to them both (same on each side) but only one of the filaments lights up, does anyone know the reason for this?

[norkep]

Could be the wrong bulbs have been put in, is there 2 connectors inside the bulb holder ??

[maniek_ls400]

I have a 1993 LS400 and My rear light bulbs have a double filament type bulb fitted to them both (same on each side) but only one of the filaments lights up, does anyone know the reason for this?

Is your LS for Europe/Japan and you mentioned about upper bulb (where tail lights are ) ? I have the same and also find wires which comes to it but WAS not used. I cat the cable and connected second filament of bulb as stop light (21W) now my LS have 2 bulbs for stop light on left and 2 on the right. If you need any help + photos just write PM.