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wiring...
Posted: Wed Aug 22, 2012 2:48 pm
by JaneHibbert
I'm going to be fitting a radio, and an electronicly operated aerial and reversing light, fog light and maybe spot lights
My question is, well questions...
Firstly in the fuse box there are two sets of wires on two fuses, one is only one with the ignition, one is on all the time - the question is what is attached to each of the two fuses?
Secondly adding all these elctronics is easy, but to which fuse box should I attach them? the right hand fuse already looks packed, and that is the ignition on one, where ideally Id like to attach them? Should I run a wire from this to a NEW secondary fuse box for all the stuff or would that put too much strain on the 35 amp fuse?
thanks so much
Re: wiring...
Posted: Wed Aug 22, 2012 3:00 pm
by bmcecosse
You may want the wireless when the Ign is NOT on - so connect it (via an in-line 5 amp fuse) to the non-ignition fuse at the box. For the others - take a feed from the NON-fused side of the Ign Fuse -and run it to a new fuse box, ideally with say 4 X 10 amp fuses - and use each fuse to supply one of your chosen add-ons.
Re: wiring...
Posted: Wed Aug 22, 2012 8:53 pm
by mike.perry
I would recommend that the various lights are wired into the lighting circuit so that the power to the switches is turned on and off by the side light switch. That way there is less chance of accidentally leaving them switched on. My spot lights are wired through the dip switch so that they turn on and off with the main beam and so do not dazzle.
Rear fog and manually operated reversing lights must have a warning light
Re: wiring...
Posted: Wed Aug 22, 2012 9:28 pm
by bmcecosse
You will overload the sidelamp switch if you do that...... You can use relays of course - or just make sure to switch them off. Can't see the need for all these extra lights myself! Is the car to be used for night Rallies?
Re: wiring...
Posted: Thu Aug 23, 2012 12:12 am
by JaneHibbert
Thanks
Radio is easy then, and that new fuse box idea from the non fused side of the ignition section sounds good. I don't need them wired into the side lights though, wired from the ignition side of the fuse box seems ideal, and lets face it if I did accidentaly leave them on I can just crank the car! such handy things minors really...
one thing though how does a relay work? If I wanted to wire up say the spotlights so theyd only work with the side lights on how could i do that?
oh and for things like new gauge lights, an oil gauge for example, where would I get the light feed for those? a spur from the instrument cluster lights maybe?
Re: wiring...
Posted: Thu Aug 23, 2012 10:00 am
by chesney
The relay works by a live feed from the sidelight circuit and acts as an automatic 'switch' (I think). Therefore, if you had a manual switch (next to your steering wheel) you could only have your fog lamps on with the sidelights anyway. Sounds like a good idea, virtually impossible to leave them on then

Re: wiring...
Posted: Thu Aug 23, 2012 10:33 am
by Alec
Hello jane,
your spotlights should be linked to your main beam such that when you go to dip the spot lights also extinguish. As mentioned earlier a relay is the way to do this.
Alec
Re: wiring...
Posted: Thu Aug 23, 2012 10:58 pm
by bmcecosse
You may want to use the spots with dip beam....handy when crossed, to show the way round corners as early as possible.
Re: wiring...
Posted: Thu Aug 23, 2012 11:16 pm
by mike.perry
Quote " If I did accidentally leave them on I could always crank start the engine"
You cannot crank start the engine when the battery is flat, you need some power.
I have a pair of Lucas Silver Sabre fog lamps wired into main beam to give a wide beam spread, the halogen headlights supply the long distance beam. The ammeter does show a slight discharge with the dynamo
Re: wiring...
Posted: Fri Aug 24, 2012 6:51 am
by Alec
Hello BMCE,
"You may want to use the spots with dip beam", true but it does contravene the regulations. Fog lights are OK on dip but not spot lights.
Alec
Re: wiring...
Posted: Fri Aug 24, 2012 1:39 pm
by bmcecosse
Spots are fine - if set so they don't dazzle. Crossed and low is great for narrow country lanes on Rallies - which I assume the car is being prepared for with this battery of lights!
Re: wiring...
Posted: Fri Aug 24, 2012 3:00 pm
by Alec
Hello BMCE,
it's up to the individual, but that is often contrary to the law.
"front fog lights: only for use INSTEAD of dipped beam in conditions of
reduced visibility - generally accepted this means less than 100 yds. Most
vehicles are wired so they come on with sidelights or dipped beam, though.
Should have a warning lamp on the dash - I would make it law that they can
only be on with sidelights and that the dipped beam and front fog lamps are
mutually exclusive, if it were my choice...
Driving lamps/spot lamps: any number allowed and can be switched
individually but all lamps over 7W must go out when you switch main beam
off, i.e. when dipped or on sidelights.
All lamps must form symmetrical pairs when illuminated.
You can have chapter and verse of Road Vehicles (Lighting) Regulations 1989
(I think) if you want. The above is a quick summary."
Low mounted lights, in my opinion, are a waste of time on other than billiard table smooth and level roads, the higher the lamp the less they are affected by rough roads and cause less dazzle to oncoming traffic.
Alec
Re: wiring...
Posted: Fri Aug 24, 2012 3:10 pm
by chesney
So presumably to comply with regulations you would have to add the relay with a feed from the main beam circuit so they can only work with the main beam (if over 7w)? Sorry, just curious

Re: wiring...
Posted: Fri Aug 24, 2012 3:27 pm
by Alec
Hello Chesney,
yes, take a feed from the main beam circuit via a control switch to energise a relay. The power side of the relay needs a heavy gauge wire to supply and feed the lamps. Correct colour coded wires make future fault finding much easier and can be bought by the metre from various specialist electrical suppliers, e.g. Vehicle Wiring Products.
http://www.vehicle-wiring-products.eu/V ... mepage.php
Alec
Re: wiring...
Posted: Fri Aug 24, 2012 3:30 pm
by chesney
Cheers Alec, just reminding myself of those lecky lessons at school. I always have been fascinated by electricity, but just not ready to fiddle with the electrics on the minor just yet

Re: wiring...
Posted: Fri Aug 24, 2012 4:26 pm
by bmcecosse
Hmmmm - I suspect the front lights I see on many moderns these days are much more than 7 watts - and they seem to be ON without the headlights whether dipped or main........ I guess they are all breaking the Regs then.....
Re: wiring...
Posted: Fri Aug 24, 2012 4:41 pm
by Alec
Hello BMCE,
yes, probably breaking the law in regards to when they should be used, i.e. often used when the visibility is well above the 100 metre mark , but not with regard to their wiring:- front fog lights: only for use INSTEAD of dipped beam"
Alec
Re: wiring...
Posted: Fri Aug 24, 2012 6:19 pm
by JOWETTJAVELIN
Jane, I would strongly recommend consulting an auto electrician on the best way to wire up all this extra stuff. Most car fires begin with electrical faults - overloading, wrong ratings etc.
Don't want to put you off - just make sure it's all safe!
Radio will need an inline fuse.
Re: wiring...
Posted: Fri Aug 24, 2012 9:15 pm
by bmcecosse
Alec - these moderns have the front lights >7 watts on ALL the time. And no need to get a specialist to wire up a few lights - it really is very very simple. Just make sure there are fuses to protect any mistakes.
Re: wiring...
Posted: Fri Aug 24, 2012 10:09 pm
by mike.perry
Modern headlamp beam patterns have rendered fog lights redundant since the beam cut off is sharp enough to prevent glare which was the problem with old style headlights.
The driving lights fitted to modern cars are also little more than a gimmic since they are just about capable of lighting the area between the front of the car and the dip beam.
When a headlamp bulb blows on a modern car why is it always the one behind the battery?