Wiring help

sean1141

Just wondering if anyone here can offer me some help with some wiring on my car..
I know basic wiring but I need help with diodes and such..

If anyone can help and is willing to answer some questions (probably stupid ones:o) can they let me know

Thanks

kirving

Can you read the wiring diagrams to start with?

sean1141

basic ones yes

kirving

What car is it? Some seem easier to follow than others? What is it that you're looking to do? Actually wire in something, or just get a better idea in general? If you can read basic diagrams, I'd say that the next step is start to have a look at any symbols that you don't understand, and go from there.

sean1141

Basically I want to wire my rear fog lights to come on with my brake lights but need to use diodes to stop the fog light symbol coming on on the dash every time I brake and another to stop the brake lights lighting if I need to use the rear fog.

Also I would like my brake light to light up with my parking light but dimmer than when it is a brake light obviously. guessing I would need a converter to change the current?

my rear lamp is as follows

brake light. single contact bulb
indicator.
reverse light.
parking light and fog light. double contact bulb

sean1141

oh and it's a 04 skoda fabia

_Brian

You first need to buy a fire extinguisher. Then start to mess with wiring.

sean1141

have one

_Brian

Figures.
Hope it's a big one.

iwillhtfu

sean1141 wrote: »

Basically I want to wire my rear fog lights to come on with my brake lights

Why??

sean1141

because I want to.

iwillhtfu

sean1141 wrote: »

because I want to.

Far to much time on your hands. :rolleyes:

sounds like a great plan to piss off every other motorist on the road.

biko

I moved this to DIY so OP can get some actual wiring help.
Let's make that happen.

sean1141

how will it piss off every other motorist on the road??

sean1141

cheers Biko. I should have put it there to start with myself

visual

Diode allows current flow in one direction only a bit like a one way valve.

To stop voltage flowing back through the fog light circuit you would place the diode in the positive supply to fog lights.

The diode is marked with a stripe or ring at one end. This is called the cathode positive voltage at other side anode will allow current flow through to the cathode.

So for your fog lights to work normally the diode would be fitted in series with the bulb. To do this it would be fitted in the positive wire feeding the fog light. If fitted wrong way round it will block current flowing and fog light won't work simply refit other way round and confirm fog light works as normal.

You will need another diode to block fog light lighting up brake lights.

The cathode of the 2nd diode connects to the cathode of the 1st

the anode of the 2nd diode connects to the positive of brake circuit.

This will allow the fog lights to work with the brake lights without warning light on dash
The fog light can also used as fog lights with out turning on brake light.

visual

Simplest way to get the brake light light up dimmer would be use a dual filament bulb the type that has brake and running light in same bulb, if the bulb socket can be adapted easy if not it will be complicated to reduce the voltage, simplest circuit would be two more diodes and a low ohm value, high wattage resistor.

I would advise giving this a miss.

I've only described one side of car in both posts so obviously would need to repeat on other side.

just so your aware all what you want to do will fail nct and it's questionable if it is legal. I doubt it is.

Don't be tempted to twist wires together and use insulation tape. You need good solid connections can't stress that enough!
Ideally you would solder connections and use heat shrink to cover joints and diodes.

If you in doubt about anything I posted seek out a good auto electrican. For the small cost involved it is much better than burning out your wiring

braddun

http://www.amazon.co.uk/s/ref=nb_sb_noss?url=search-alias%3Daps&field-keywords=fog+lights+kit&rh=i%3Aaps%2Ck%3Afog+lights+kit

Special Circumstances

braddun wrote: »

http://www.amazon.co.uk/s/ref=nb_sb_noss?url=search-alias%3Daps&field-keywords=fog+lights+kit&rh=i%3Aaps%2Ck%3Afog+lights+kit

???



Anyway, back on topic...
I can't see 'the rear fogs coming on every time you brake' passing NCT. For the good of anyone stuck behind you.

Do you have "blown bulb" detection in that car? I'd tap off a circuit in a modern car to control my own accessories, I'd be slow to force a car's own circuit to a state the bcu didn't expect! I'd want to be pretty sure! A relay in the side light circuit controlled by acc or ign will give you "drl" style lights front and rear.

sean1141

Cheers for the input visual. As I said I have basic wiring skills and tools but most of the stuff I have been working on are older tractors etc or simple jobs like fitting front spot lights to cars.

Special Circumstances wrote: »

Do you have "blown bulb" detection in that car? I'd tap off a circuit in a modern car to control my own accessories, I'd be slow to force a car's own circuit to a state the bcu didn't expect! I'd want to be pretty sure! A relay in the side light circuit controlled by acc or ign will give you "drl" style lights front and rear.

No blown bulb warning light in the car.

I don't follow what you mean in the last sentence?

Special Circumstances

Sorry, thought you wanted something relatively sensible like auto rear lights.
You want brake lights as rear lights and fog lights as brake lights. Would you consider getting good quality led bulbs instead - light up quicker and can give brighter light for less power consumption. (Assuming you get decent ones rather than lucky dragon much shininess leds from eBay)

Have you ever tried running the electricity off the gas and the gas off the electricity?

sean1141

There is a output on the light switch for drls on my car. It is ignition live and switches off when you switch on side lights. If I wanted to do what you are talking about it would be very easy but Im talking about something totally different as stated it post #5. I thought I made that clear but obviously not.

Any way this is what I would like except for the flashing middle brake light and indicators/reverse lights

PukkaStukka

I don't know those small Skoda's well but their VW counterparts use a CAN bus system and mucking about with wiring is an absolute No-No. If, for example, you want to wire a trailer socket, its now no longer the case of just splicing and joining cables. Some additional kit needs purchasing to do it properly. You'll know soon enough if ABS or ESP system errors start appearing for no good reason

sean1141

mine is not can bus. there is no box needed to fit a trailer socket