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Fog lights
Johnmor - 10/12/20 at 06:42 PM

Hi all

I realise the IVA manual states-

"The rear fog lamp(s) must only illuminate when dipped beam, main beam or front
fog lamps are lit (see alternatives in Notes 3 and 4)."

Its easy to achieve with just dip, but will turn off the fog light when main beam is selected , have many had the fog working with both Dip and Main beam, seems the most sensible option as you need to be seen from behind when in either main beam or dip on a foggy night

Do they assune you wont use man beam if the mist or fog is dense enough to require the fog light?

thoughts please

john


steve m - 10/12/20 at 07:44 PM

Using full beam in Fog, will result in you seeing nothing at the front! way way to bright
hence low beam is used, or back in the day fog lights that were yellow

dont forget that for the idiotic IVA , the fog lights still have to be "E" marked


Mr Whippy - 10/12/20 at 08:11 PM

The front and rear fog light switches live feed should come from headlight switch before it goes to the headlight relay used for selecting high or low. Mind too that there must be an indicator lamp on the switches for both of the fog lights with the correct symbol which itself must illuminate when on.


Deckman001 - 10/12/20 at 10:16 PM

I hope i got this right, I took a feed off each of the dipped and main headlight wires from the relay, I used diodes to stop each one feeding the other so that the extra wires would then feed the relay that stops it coming back on if the fog light is left on when the lights are turned off and then back on again the next time the lights are turned on again.

Another big thanks to CBS who sell those relays.

Jason


Johnmor - 10/12/20 at 10:46 PM

Hi , thanks for the reply

The Sierra switch uses switched earth to control full and main beam, I'll just link to the dip earth as a trigger for the fog lights, the warning light will act to tell me if I've left them on, they will only work with dpped light but thay should be ok for IVA

Dont plan in driving in snow or fog anyway, lol


westf27 - 10/12/20 at 11:04 PM

My understanding is the rear fog can only operate if dipped,main beam or front fogs are used.
Also the need to wire rear fog so that it has to be reactivated if accidentally left on from previous use is not required
For amateur builds.Southampton IVA confirmed that as correct.
Would welcome comments on that if you feel it’s wrong.


Mr Whippy - 11/12/20 at 12:14 AM

No your right about not requiring the fog lights to reset if the lights are turned of for the IVA.


Schrodinger - 11/12/20 at 03:42 PM

I have to say I don't think you are correct. My Stylus went through IVA at Norwich in 2017 and passed with no problems.
I would suggest you ask at the IVA centre where you are intending to submit your car for a test and see what they have to say.


CosKev3 - 11/12/20 at 04:00 PM

quote:
Originally posted by Johnmor
Hi all

I realise the IVA manual states-

"The rear fog lamp(s) must only illuminate when dipped beam, main beam or front
fog lamps are lit (see alternatives in Notes 3 and 4)."

Its easy to achieve with just dip, but will turn off the fog light when main beam is selected , have many had the fog working with both Dip and Main beam, seems the most sensible option as you need to be seen from behind when in either main beam or dip on a foggy night

Do they assune you wont use man beam if the mist or fog is dense enough to require the fog light?

thoughts please

john


Do exactly what you've quoted from the manual!

Aslong as they don't work with the sidelights and you have a tell tail
with the correct rear fog light symbol on it you will be fine.

Fitting a controller that stops the fog light coming back on with headlights is as it states in the IVA manual,an 'alternative' not a requirement.


40inches - 11/12/20 at 06:51 PM

quote:
Originally posted by CosKev3
quote:
Originally posted by Johnmor
Hi all

I realise the IVA manual states-

"The rear fog lamp(s) must only illuminate when dipped beam, main beam or front
fog lamps are lit (see alternatives in Notes 3 and 4)."

Its easy to achieve with just dip, but will turn off the fog light when main beam is selected , have many had the fog working with both Dip and Main beam, seems the most sensible option as you need to be seen from behind when in either main beam or dip on a foggy night

Do they assune you wont use man beam if the mist or fog is dense enough to require the fog light?

thoughts please

john


Do exactly what you've quoted from the manual!

Aslong as they don't work with the sidelights and you have a tell tail
with the correct rear fog light symbol on it you will be fine.

Fitting a controller that stops the fog light coming back on with headlights is as it states in the IVA manual,an 'alternative' not a requirement.

What Kev said, the reset is only intended for cars with Can bus


Mr Whippy - 11/12/20 at 07:04 PM

Tbh my old fiesta and the vw Up both simply have a rotary switch that turns of the fog light when the switch is set to off. It's entirely mechanical.


gremlin1234 - 11/12/20 at 07:06 PM

quote:
Originally posted by CosKev3
Do exactly what you've quoted from the manual!

Aslong as they don't work with the sidelights and you have a tell tail
with the correct rear fog light symbol on it you will be fine.


and aligned squarely and at the correct height/location