Rear Rh light _ double filament

[ollylever2020]

Evening I've been working on a C15 to bring it back from the scrap heap. Final challenge that has me stumped is that my rear Rh tail light, top light double filament works perfectly for one filament ( break light) but the tail light just won't work. All other lights working perfectly, any help would be massively appreciated, this is my first project so I've been learning as I go. Cheers Olly

[MattBLancs]

Starting with the basic stuff as said learning:

- check bulb is ok with multimeter (set on ohms)
- if had been standing a good while, consider if bulb terminals are tarnished/ oxidised = clean up with wire wool.
- same for corresponding terminals in the lamp cluster (bulb connection) = wire wool quick rub can't hurt.
- also check the electrical connection to the lamp unit / bulb carrier= again oxidation here can give odd faults (bad earth and lights that flash alternately with indicators is a common one.

- next put multi meter onto volts (normal 20v setting, DC) and check if you have 12 volts at the bulb holder with brake pedal depressed. Note some brake lights don't work without ignition on (but sidelights normally do without key in)

- mentions right hand rear, so assume left rear is ok. That suggests brake pedal switch is ok (otherwise get none!)

Not 100% on C15 light arrangements (can picture those big rectangular clusters but not sure what does what beyond that!) But a side note: early 306 had two bulbs for tail light each side at rear. Of these, only one bulb did brake light. However BOTH had twin filament bulbs - so the innermost ones each side only acted as 5w tail light and the brighter 21w filament was never used!

Odd arrangement but worth mentioning incase the C15 does a similar silly trick.

[GiveMeABreak]

There's only 2 bulbs in the rear lights on a C15, so make sure these are correct: the top one is a 12V-P21W and the lower one a 12V-R5W.