S3 Fog/Drive light switch

[edsj]

Dear TVRPH's

Although posts suggest that those lights are pretty useless I would like to make them work any way. I am no electrical engineer so I am looking for some advise. Without having tested anything, at this moment the lights do not work nor does the indicator/light in the switch. Does that give any hints? Does this switch light has to work, for activating the relais?

Thank you in advance!

Edsj.

[GreenV8S]

The driving light wiring on my V8S is completely bonkers, and perhaps yours is similar. On mine, the power feed to the headlamp main beam operates a relay that supplies power to the fog/drive lamp switch, so the switch is directly switching the supply to the driving lamps.

I've seen all possible combinations of fog / driving lamp assemblies coming on with high and dipped beams and I don't know how many of these came from the factory like that, but as far as I can see the wiring on mine was original. If yours is like this then the switch has to be up to handling quite a few amps, which the original switches seemed quite marginal at even when they were in good condition.

There was a post within the past few months pointing out where these switches came from, so if you think you need to replace it, that ought to be possible. If your wiring is as daft as mine and you're feeling keen, that would be a good time to redesign the wiring so that the main current only goes through the relay and not the switch.

[edsj]

Thanks GreenV8S! Re-designing is a bit too much for me I'm afraid. I will see what I can make of it..

[edsj]

After installing new d'light units as the old ones were rusted and cracked and some fiddling with the connectors prior to MOT nothing worked... But guess what, at MOT today the tester fiddled a bit more and now they work!! Magic! In my case only with the full beams ON. (S3 1991). Passed MOT btw. first time :-))
The indicator light inside the switch does not work though. So now try to adjust the units a bit higher. Won't be easy as they are a very tight fit in those holes.

Regards Edsj

[TurboTony]

My understanding is that these are driving lamps and come on with main beam. They are not switched independently. Any lamp operating with dip beam would have to be switched separately, have a fog lens pattern and only used in conditions of fog or falling snow. It would not be correct to use the existing lamps as an enhancement for dip beam as this would dazzle other road users.

[edsj]

Makes sense

[DamianS3]

Well mine work with the side lights on, separate switch and tell tail so I guess they are fog lights xx current led bulbs are rubbish though so no chance of. Dazzling anyone. Going back to the 55w bulbs next time I'm under there.

Damian S3

[edsj]

Now that the lights are working: can the light/bulb in the switch be replaced? Or am I exaggerating :-)

[DamianS3]

Yes easy..

http://www.pistonheads.com/gassing/topic.asp?h=0&a...

You can get a bulb from Halfords.

Thanks

Damian S3

[tel595]

TurboTony said:

My understanding is that these are driving lamps and come on with main beam. They are not switched independently. Any lamp operating with dip beam would have to be switched separately, have a fog lens pattern and only used in conditions of fog or falling snow. It would not be correct to use the existing lamps as an enhancement for dip beam as this would dazzle other road users.

Mine do the same Tony...

[GreenV8S]

I don't know whether this is how they left the factory, but over the years I must have seen every possible permutation of fog and driving lamps wired as fog and driving lights on different cars.

[RayTVR]

On my S3 at least;

They left the factory as fog lights and I have a separate switch on the panel with the other rockers. This was an option and included the bonnet change of course.

On my car they were later wired in (via relays) to operate as driving lights and mine are triggered directly by main beam selection. Ring RL020 spots fit nicely and are cheap. There is a long saga of there fitting during the early 90's as they were originally done badly, and the subsequent fitting by a proper auto electrician resulted in a claim against the dealer..

[tvrgit]

tel595 said:

TurboTony said:

My understanding is that these are driving lamps and come on with main beam. They are not switched independently. Any lamp operating with dip beam would have to be switched separately, have a fog lens pattern and only used in conditions of fog or falling snow. It would not be correct to use the existing lamps as an enhancement for dip beam as this would dazzle other road users.

Mine do the same Tony...

Chaps...

These are TVRs. The first rule of TVR ownership is "never assume that your car is the same as anybody else's". Mine are fog lamps. They have a fog lamp lens and are wired through an original switch to only come on with dip beam (or is it sidelights? Can't remember). I have the original little booklet supplied with the car that shows the controls, and it shows that switch in that place for that purpose. Since the wiring to the switch is part of the same dodgy electric spaghetti loom as the rest of the car, I have to assume that is how my car (at least) left the factory.

I would prefer if they were driving lamps, TBH, because front fog lights (on any car) serve absolutely no useful purpose except in the most extreme weather, which I have encountered only one or twice in darkness, in all the time I have been driving. And when it's that bad, Glen's bog roll dispenser is far more useful than fog lamps in any case.

[GreenV8S]

tvrgit said:

And when it's that bad, Glen's bog roll dispenser is far more useful than fog lamps in any case.

[edsj]

Thanks DamianS3! (bulb)

[TurboTony]

An interesting census at S Club. Which later cars have driving or fog lights.

[edsj]

S3 August 1991 driving lights