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Rear fog lights

Posted: 03 Jun 2009 09:05
by Philip
When are the fog lights supposed to work ? Mine only work with dipped beam on and go off when I switch to high beam. That doesnt make sense to me, surely they should be on regardless of which beams are selected. (1981 DHC)

Still standing !
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Posted: 03 Jun 2009 09:17
by john
Front fogs work with the sidelights on i think and the rear only work as you say with the headlights

[8 whole cylinders worth of punch to ram the world through the windshield and out the rear view mirror. Car & Driver]
1981 Grinnall TR7 v8
1981 Black FHC
1979 & 1980 Black Premium FHC(laid to rest) Sorry :-(
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John

Posted: 03 Jun 2009 09:29
by TR Tony
Rear fogs on with dip beam & off with main beam is correct Philip.

I think the idea is that if visibility is good enough to allow use of high beam then you don't need the fogs on!

Tony
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<font size="1">1981 2L FHC Cavalry Blue
1980 3.5L V8 DHC Jaguar Regency Red - sadly sold!</font id="size1">

Posted: 03 Jun 2009 10:32
by busheytrader
As per Tony, my lights work the same.

Full beam in fog reduces visibility so the logic must have been at the time:

full beam = good visibility = no need for rear fog lights.


Adam

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TR7 V8 DHC Jaguar Solent Blue. 9.35cr Range Rover V8, Holley 390cfm, JWR Dual Port, 214 Cam, Lumention, Tubular Manifolds, Single Pipe Exh, 3.08 Rear, 200lb Spax & PolyBushes, Anti- Dive, Granada Vented Discs & Calipers, Braided Hoses, 4 Speed Rear Cylinders, Uprated Master Cylinder & Servo, AT 5 Spokes and Cruise Lights. No Door Stickers. Mine since July 1986, V8 from 1991

Posted: 03 Jun 2009 17:25
by danny
My rear fog works on dipped and full beam. Our modern cars are the same.

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Danny
1980 TR7 fhc <b><font color="green">Brooklands green</font id="green"></b>
1967 Spitfire Mk3 <b><font color="red">Signal red</font id="red"></b>
1953 Ford Anglia E494A <b><font color="black">Black</font id="black"></b>
View my Blog http://www.waringstowntr7s.co.uk/blogs/index.php/danny
http://tr7-n-spitfire.blogspot.com/

Posted: 03 Jun 2009 17:57
by Howard722
Fogs on with dipped beam only is correct,it`s all down to the way the wiring is (was) done for the motors as well as the lamps!!-it assumes you don`t need high beam in fog due to back glare.[8D]

Enjoy& regards Image

Posted: 03 Jun 2009 21:11
by danny
Just checked out my rear fog lamp, my original hand book for the car says that the fog lamp circuit operates only when the side lights are on.
This is the operation, the lamp is lit when the side, dipped & main beam is on, I think this must be the orignal design setup.

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Danny
1980 TR7 fhc <b><font color="green">Brooklands green</font id="green"></b>
1967 Spitfire Mk3 <b><font color="red">Signal red</font id="red"></b>
1953 Ford Anglia E494A <b><font color="black">Black</font id="black"></b>
View my Blog http://www.waringstowntr7s.co.uk/blogs/index.php/danny
http://tr7-n-spitfire.blogspot.com/

Posted: 05 Jun 2009 09:26
by bmcecosse
Wire them up any way you like - just don't use them - except to pass the annual MOT!
Hellish things - causing terrible back glare to those behind - and completely masking the brake lights. I suspect they have caused many more accidents than they have ever prevented!

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Posted: 05 Jun 2009 09:59
by Odd
<blockquote id="quote"><font size="1" face="Century Gothic, Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"> ... Hellish things - causing terrible back glare to those behind <hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote"> If it does (and <u>if</u> it is fog-light-weather) - then you're far to close, mate - and <u>you</u> are the traffic hazard!

<blockquote id="quote"><font size="1" face="Century Gothic, Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"> I suspect they have caused many more accidents than they have ever prevented! <hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote"> If they were used the way they were invented, i.e. a single light (sitting low on the rear side of the vehicle
towards the middle of the road) and only active when justified. Then they are GREAT safety enhancers...
But if active in other times they are a nuisance.
And fitted in pairs, left AND right, they miss the original idea completely and aren't as safety enhancing
as a single one.

So;
A <u>single</u> high power light, <u>low</u> on the (right in your imperial case, left for us in the rest of the world) side
- and <u>only</u> possible to have active in connection with dipped headlights - is a great invention for bad
viz weather conditions.
If anyone feels that light is causing a terrible glare - he/she is to close to be safe.

(Or it's activated in the wrong type weather - which is a traffic offence...)

Posted: 05 Jun 2009 13:29
by busheytrader
Hi Odd,

I've always preferred fog lights away from the main cluster so that the other lights aren't glared out by the them.

What's your thinking behind 1 x fog light is better than 2 x fog lights?

Cheers,


Adam



Image

TR7 V8 DHC Jaguar Solent Blue. 9.35cr Range Rover V8, Holley 390cfm, JWR Dual Port, 214 Cam, Lumention, Tubular Manifolds, Single Pipe Exh, 3.08 Rear, 200lb Spax & PolyBushes, Anti- Dive, Granada Vented Discs & Calipers, Braided Hoses, 4 Speed Rear Cylinders, Uprated Master Cylinder & Servo, AT 5 Spokes and Cruise Lights. No Door Stickers. Mine since July 1986, V8 from 1991

Posted: 05 Jun 2009 13:38
by bmcecosse
I was commenting on the line of cars - all travelling along at 10 mph with their rear fogs ON! Eavh one blinding the one behind. It's hopeless - how am I supposed to see past that lot to overtake them !! ??
In this country - these wretched lights are gleefully switched on at the slightest hint of MIST - and then left on for the next week or two - just in case the mist returns!!
They serve absolutely NO useful purpose - what are they supposed to do - melt away the fog ??

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Posted: 05 Jun 2009 14:42
by XSeries
Here here!
The sad fact is that few people read the highway code and realise that they should only activiate their rear fog lights when visibility is less than 328 feet (100 metres). The markers alongside the dual carriageways and motorways are that far apart - but how often can one see the next 2,3 or even 4 yet still have the darn rear fog lights on!
I have never used them on the TRs as the weather has never demanded it! It is rare that we have thick fog now that necessitates their use.
One low mounted would be better than those alongside brake clusters where one cannot be sure of the infomration being provided - or too much glare and no one is NOT too close if they are glaring at 1/8 mile!

Rule 236
You MUST NOT use front or rear fog lights unless visibility is seriously reduced (see Rule 226) as they dazzle other road users and can obscure your brake lights. You MUST switch them off when visibility improves

Posted: 05 Jun 2009 16:29
by Odd
<blockquote id="quote"><font size="1" face="Century Gothic, Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"> Hi Odd,
... What's your thinking behind 1 x fog light is better than 2 x fog lights? <hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote"> The original single rear fog light idea was that one single high intensity light couldn't be mistaken for (a pair of)
brake lights. So one is far better than two, and it should be positioned low down in the middle or on the drivers side...

<blockquote id="quote"><font size="1" face="Century Gothic, Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"> ... It's hopeless - how am I supposed to see past that lot to overtake them !! ?? <hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote"> Simple, you're not supposed to overtake anything in the low viz conditions that legally allow for fog light use
- not even at 10mph or less...

And if it isn't low viz conditions - you just have to adapt your habits. Cursing is allowed in this situation... [}:)]
Tip: Several high intensity pencil beam lights (hitting through the opponents rear view mirrors) is usually a good persuader...
(Or make a call, sit back - and wait 'til the Man fines them for showing unlawful lighting on the car.
Laughing is allowed in this situation... [:)])

Posted: 05 Jun 2009 21:31
by bmcecosse
And get 'done' for using phone while driving!! Aye right!

As an aside -I decided to get rid of the ghastly dangly single rear fog warning light on my TR7. Changed the outer red section bulb holders for double filament type with 5/21 bulbs fitted for side/brake lighting. This leaves the inner red sections free to be my fog warning lamps - 21 watt bulbs fitted. Much much neater - not 'exactly' legal by Construction and Use regs - but the MOT man will pass them ok - and I NEVER use them anyway, so there will be no blinding or masking of brake lights!

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Posted: 05 Jun 2009 22:08
by saabfast
I have to admit, I do use them on motorways in fog (not in the '7 which I do not use in the winter but in other cars). I find that there is occasionally fairly thick fog on parts of the M25 and M40 that I travel regularly and that standard rear lights do not show until you are close to the car in front. At least rear fog lights - used in the right circumstances - reduce the chances of some idiot running into the back of you.

Alan
Saab 9000 Stg 1
Saab 9000 2.3 FPT Auto
'81 TR7 DHC
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