rear light/brake light wiring

[Andie]

Hello. Have been happily running in my Li - just 150 klicks to go!

However.. my carello rear light blew yesterday, not a big problem as I carry a spare, but when the rear blew the brake light then also didn't work unless the bottom on/off switch was put into the middle position (the one that is not really a position and only for transition between on/off to prevent bulb blowing).

12v casatronic, non battery, wired to a late Li loom so as to use the later three <edit> wire</edit> brake pedal.
Also rear light is always on, not a problem as I always have lights on, but that might be a dodgy switch.

is it normal that the brake light stops working when the rear blows?

Thank you. Andie

[Wack]

I'd check the rear light unit for a good earth and that the sprung contacts are sitting correctly on the bulb contacts.

[Andie]

Thank you Wack. I checked all that and it's fine.

I suspect the switch might be dodgy is why the back light is always on, although the headlight does on/off.

I can't get my head around why the brake light would cease to work when the tail lamp is blown though...

Also - my rear lamps (Halfords but others are available) is 12v 21/5 - which of the elements is tail and which is stop lamp? I may have them the wrong way around.
also my brake light switch is 2 wire, not three as I originally stated.

Thanks again - Andie

[CHRIS in MARGATE]

Stop light is always the brighter of the 2.
Both filaments work completely independently of one another but if you have no earth at the rear light then the power will look for a way to go and probably why both cone on and die together.

[grandpa]

Hi Andie
21 watt is brake light 5 watt is rear light . Remember the brake light switch operates opposite to a normal switch in that plunger In is off and plunger out is on.If you have not fitted brake lever the brake light will stay on.Black wire normally feeds 5watt rear light.Traditional bulb has offset pins so you can't fit it incorrectly (but you could have your wires crossed!)the design of some switches is awful and I have had the metal plunger of brake switch short 12v to ground.Check switch with meter
Grandpa

[gaz_powell]

I had the same - out of the blue when you turned the lights on the brake light came on permanent - I first tried a new switch still the same so striped the light unit out and found a bad earth. Sorted the earth and hey presto.

[CHRIS in MARGATE]

Last year I had a brand new switch bought from a dealer where the switch operation was reversed. Took it back with my meter to show.

[Bothie]

Always on!
I have installed a 12V AC electronic kit (no battery) to my Li series 3 which successfully starts and runs lights but the brake light wont switch off on the one pole switch.
I read somewhere a 2pole switch is required. The original wire to the 1 pole switch is pink. Can anyone tell me where the other wire runs back to?

[HxPaul]

You want a 2 pole brake light switch.The pink goes from the switch to the brakelight.The other wire goes to the regulator.

[Bothie]

Thanks HxPaul.