One lamp, two functions?
40inches - 6/10/16 at 10:59 AM
I have a high level brake light fitted, but want to use it as the rear fog light as well as.
So, one lamp with two different feeds, will fitting blocker diodes in the feed wires work? If so what type and size?
owelly - 6/10/16 at 11:10 AM
I used a relay to do the same job.
40inches - 6/10/16 at 11:15 AM
quote:
Originally posted by owelly
I used a relay to do the same job.
That was my first option, but a couple of diodes would make the job far simpler 
Lazy? Me?
loggyboy - 6/10/16 at 11:38 AM
Lens refractors are different for fogs/brakes - so wont give the correct output.
While not an MoT issue, C&U state rears fogs should have approval markings AND
No rear fog lamp shall be fitted to any vehicle so that it can be illuminated by the application of any braking system on the vehicle[i/]
[Edited on 6-10-16 by loggyboy]
40inches - 6/10/16 at 12:51 PM
quote:
Originally posted by loggyboy
Lens refractors are different for fogs/brakes - so wont give the correct output.
While not an MoT issue, C&U state rears fogs should have approval markings AND
No rear fog lamp shall be fitted to any vehicle so that it can be illuminated by the application of any braking system on the vehicle[i/]
[Edited on 6-10-16 by loggyboy]
High level brake lights carry the same E markings as Rear fog lights, so same light output.
r1_pete - 6/10/16 at 02:34 PM
How about using a modern bike tail light, most have 2 twin filament bulbs, use the 21W filaments, one fog one brake....
No idea what C&U or Mr MOT would make of it though....
40inches - 6/10/16 at 03:24 PM
quote:
Originally posted by r1_pete
How about using a modern bike tail light, most have 2 twin filament bulbs, use the 21W filaments, one fog one brake....
No idea what C&U or Mr MOT would make of it though....
I have both lamps fitted already Pete, but I will be fitting a diffuser and the bottom fog lamp is in the way. I was just going to use the high level
brake light as the fog light ( the same E number) But would like to retain the brake light facility
loggyboy - 6/10/16 at 03:44 PM
quote:
Originally posted by 40inches
High level brake lights carry the same E markings as Rear fog lights, so same light output.
Wattage of bulbs is, but as IVA is fussy about E marking, I cant see how a tail light lens would share the same approval for C&U - also no
arguments about the other section i quoted.
quote:
Originally posted by r1_pete
How about using a modern bike tail light, most have 2 twin filament bulbs, use the 21W filaments, one fog one brake....
No idea what C&U or Mr MOT would make of it though....
But that wouldnt work as You get 1x 21w bulb and x 10w bulb, where as brakes and fogs both need 21w.
40inches - 6/10/16 at 04:46 PM
quote:
Originally posted by loggyboy
quote:
Originally posted by 40inches
High level brake lights carry the same E markings as Rear fog lights, so same light output.
Wattage of bulbs is, but as IVA is fussy about E marking, I cant see how a tail light lens would share the same approval for C&U - also no
arguments about the other section i quoted.
quote:
Originally posted by r1_pete
How about using a modern bike tail light, most have 2 twin filament bulbs, use the 21W filaments, one fog one brake....
No idea what C&U or Mr MOT would make of it though....
But that wouldnt work as You get 1x 21w bulb and x 10w bulb, where as brakes and fogs both need 21w.
What is your problem?
The brake light in question has the same E markings as the Fog light in question, I may be pushing 70 but my eyesight is not that bad.
I choose to ignore your other "argument" because I just don't care!
I take it you have no answer to the main question I asked?
rachaeljf - 6/10/16 at 05:28 PM
Firstly, I believe the fog/brake light would need to be between 850 and 1000mm above the road. If it's an LED light, a 1N54xx diode fed from the
brake light circuit should be ok. You won't need a diode on the rear fog feed. If it's a filament lamp, something a bit chunkier like a
P600A diode should be ok. Alternatively use a relay actuated by the brake light circuit.
r1_pete - 6/10/16 at 05:29 PM
Loggy my last 4 or 5 bikes, 916, Blade, R1, XJR, the tail light has 2 x 12v 21/5 watt bulbs, tail light uses both 5W the brake both 21W.
Dave I was coming from the view that when the fog light is on, you would not have high level brake light function, to have both you need 2 x 21 watt
bulbs. I realise though you're after minimal change and that brake light is quite tidy, is there a way you could add a second bulb??
40inches - 6/10/16 at 05:46 PM
quote:
Originally posted by rachaeljf
Firstly, I believe the fog/brake light would need to be between 850 and 1000mm above the road. If it's an LED light, a 1N54xx diode fed from the
brake light circuit should be ok. You won't need a diode on the rear fog feed. If it's a filament lamp, something a bit chunkier like a
P600A diode should be ok. Alternatively use a relay actuated by the brake light circuit.
Thanks Rachael, just what I wanted
"Dave I was coming from the view that when the fog light is on, you would not have high level brake light function, to have both you need 2 x 21
watt bulbs. I realise though you're after minimal change and that brake light is quite tidy, is there a way you could add a second
bulb??"
See what you mean Pete, the other brake lights would still work OK, so I think that would be acceptable?
gremlin1234 - 7/10/16 at 12:02 AM
rear fog requires 'F' or 'B' markings as well as 'e' or 'E'
and they have quite a lot of regulation as to where they can be positioned, and their switching arrangements.
however, since its a 'Q' registered car, it does not need a rear fog light!
Huttojb - 7/10/16 at 06:46 AM
quote:
Originally posted by gremlin1234
however, since its a 'Q' registered car, it does not need a rear fog light!
Sorry to get involved in this conversation, but is the above correct. I hate my rear fog light and really want to remove it. I don't plan to
drive my car in the fog so I see it as such a waste.
steve m - 7/10/16 at 07:44 AM
I have a strip light/ high level brake light, on my 7, that has passed the MOT every time, and is wired so that in normal driving the light is a brake
light, and if the fog light switch is on, it only operates as a fog light, and not the brake lights
The wiring is easy, as you will have one earth and two feeds one from the brake light switch, and one from the fog light switch
put a diode in the brake light wire, the right way round and that will block the power to the BL, once the FL are switched on
steve
907 - 7/10/16 at 08:55 AM
I would have thought that in situations where a fog is needed then the high level brake light becomes even more necessary.
Think of coming home from a show and getting caught in a heavy downpour, maybe on a duel carriageway or motorway, and
the spray from the HGV's reduces visibility. I'd want both lights.
Paul G
40inches - 7/10/16 at 08:59 AM
quote:
Originally posted by 907
I would have thought that in situations where a fog is needed then the high level brake light becomes even more necessary.
Think of coming home from a show and getting caught in a heavy downpour, maybe on a duel carriageway or motorway, and
the spray from the HGV's reduces visibility. I'd want both lights.
Paul G
High level brakes lights on a 7 are very rare beasts, having the HL light as a fog light is the same as the brake light being on all the time, is it
not?
907 - 7/10/16 at 04:58 PM
quote:
Originally posted by 40inches
quote:
Originally posted by 907
I would have thought that in situations where a fog is needed then the high level brake light becomes even more necessary.
Think of coming home from a show and getting caught in a heavy downpour, maybe on a duel carriageway or motorway, and
the spray from the HGV's reduces visibility. I'd want both lights.
Paul G
High level brakes lights on a 7 are very rare beasts, having the HL light as a fog light is the same as the brake light being on all the time, is it
not?
A red light to me says many things.
A red light appearing out of the gloom says, there's a car in front.
A red light suddenly appearing says, there's a car stopping.
A flashing red light says, bicycle.
A red light above a door says, "bugger," I've forgot my wallet.
I have a white brake light in the roll over bar that is quite inconspicuous.
When it comes on (obviously red) it surprises a following tailgater and consequently has double the effect.
Cheers,
Paul G
Description
Toys2 - 7/10/16 at 06:46 PM
I wanted the same thing, my Striker is already registered, I was refurbing the rear lights, here's my totally NON IVA solution
All of my rear lights are on small connectors, so I "ahem" adjust them for the MOT
It's like your picture, but with a slightly different number plate light
I have a numberplate light similar to this (dump the bracket)
Clear 12V Motorcycle Motorbike Tail Light LED Rear Brake Lamp Cafe Racer Bobber
It has 2 functions - 3 wires
- Number plate - but note it also emits a dim red lightout the back when the number plate light is on (like a sidelight) - not strictly legal
- Brake light
MOT set up
Number plate light with a strip of carbon vinyl wrap over the back masking the rear facing light
High level light, connectors swapped to make it my fog light
No additional brake light
Rest of the year
I swap the connectors around so the high level light is my brakelight
Remove the tape off my number plate light and connect the bright red light as the fog
snowy2 - 8/10/16 at 08:26 AM
i thought that brake lights and fog lights had to have a minimum separation distance...that would preclude them having the same bulb surely?
snowy2 - 8/10/16 at 08:31 AM
C+U FOG LIGHT REGULATIONS
here...
look at part 10 electrical connections.
snowy2 - 8/10/16 at 08:34 AM
and part 2, position. sub paragraph d, a minimum of 100mm between fog lamps and brake lights...
it would seem that to use a high level light used as a fog light would be illegal.
there is a small possibility that it can invalidate your insurance.
Toys2 - 8/10/16 at 11:20 AM
I don't think that this fouls any position regulations
The "High" level is still lower than 1000mm, it does need to me a minimum of 250mm from the ground
The vertical separation between the brake and fog lights is about 400mm
The issues I see are if the lenses are not correctly marked, but for most the intensity of brake and fog lights are very similar
