Spot Light wire relays law

[Guest]

Hi guys,

I am just about to change my front roll cage on my 110 to a set of 4 angel eye spots fitted with 55w bulbs.

I currently have a set of cheap normal spots, when I wired these up I took the feed for these from the alternator via a waterproof fuse and wired up through a 40amp relay. they are switched via an illuminated switch in the cab and not connected to the main beam however the switch takes it's feed from an ignition live so can't leave them on when engine is off, they have 55w H3 bulbs in them, although bright not as bright as I would expect for 220w of light!

Few questions:

1. What is the law around angel eye spots road use etc if having them as running lights (truck mode)

2. Clearly I will fit a switched relay to the angel eye side of the lights so that they can be controlled separately from the side lights. However my question is one relay enough for the 4 lights on the main light side (55w ea) or should I split them between two relays?

3. If I do run two relays can I switch them off the same source or is it better to have them on separate switches?

4. I currently don't have them wired into the main beam, if I was to do this I would still keep the isolation switches but what is the Law around having them wired into my main beam for road use? I have read lots of different things but not sure about 4 spots as most talk about articles talk about 2 spots and maximum wattage per bulb.

Whilst I am fettling I also have the little side lights in my new crystal headlight bowls, I didn't wire them up, however again interested in the law around these, If I was to wire these up should I just take the feed from the side lights or go down a relay route?

Sorry last question!! has anyone ever used the H3 type LED bulbs? if so what was your impresion against normal 55w bulbs?

Welcome your feedback,

Cheers, Jason.

[western]

Whilst I am fettling I also have the little side lights in my new crystal headlight bowls, I didn't wire them up, however again interested in the law around these, If I was to wire these up should I just take the feed from the side lights or go down a relay route?

I fitted wired my crystal lens headlights with sidelights inside last weekend & connected into the existing sidelight wiring, they are additional lights so so long as the original sidelights are working there should be no problem with sidelights within the headlight bowls.

as for the other 'marker' lights HGV's are legal because the lights are in front of the front axle centreline not so on any Land Rover. having 4 55w bulbs on a single relay is pushing it a bit IMHO, better to use 2 relay one per pair of lights & probably get a better light output as the relay isn't working to full capacity, a single switch operating the 2 relay should be fine, most switches can easily cope with 10amps relays only need a small switching current.

roof lights operating with main beam IIRC isn't stricly legal, but as the would go out when main beam is switched to dip, you may not have any problem.

[sean f]

Basically any additional lights on the front of the vehicle MUST only operate with main beam and MUST switch off when you dip the headlights.

The exceptions to this is if covers are fitted to the lights for road use and they are classed as "off road only", the covers must be in place on the road.

The other exception is FOG lights (with emphasis on the FOG), these must be fitted low and can ONLY be used in reduced visability, the use of fog lights (and anything other than the dip beam / side light is classed as a fog light) in normal conditions is illegal and you can get points and a fine for it. Legally there is no such thing as "driving lights". I suspect lorries may come under slightly different regulations but I am not sure about that.

[Guest]

Thanks for the quick responce Western and Sean.

Cheers, Jason.

[Guest]

Basically any additional lights on the front of the vehicle MUST only operate with main beam and MUST switch off when you dip the headlights.

The exceptions to this is if covers are fitted to the lights for road use and they are classed as "off road only", the covers must be in place on the road.

The other exception is FOG lights (with emphasis on the FOG), these must be fitted low and can ONLY be used in reduced visability, the use of fog lights (and anything other than the dip beam / side light is classed as a fog light) in normal conditions is illegal and you can get points and a fine for it. Legally there is no such thing as "driving lights". I suspect lorries may come under slightly different regulations but I am not sure about that.

Sorry Sean, Just read your responce again, are you saying that the side light bulb within the crystal hedlamp bowl is ilegal for road use? or were you just refering to additional lights?

Cheers, Jason.

[western]

Lots of older & modern cars have the sidelight 'pilot' light inside the headlights & as the Crystal headlights are 'E' approved the comply with UK/European vehicle lighting regs so are OK. plus they are 'additional' lights not instead of, the original sidelights remain as the obligatory legal lights.

[Maverik]

To work out the rating of components in an electric circuit you can use P=I*V where P-Power (watts) I-Current (amps) V-Voltage (volts)

So your Power is 220w/12v (worst case) = 18.33 amps (drawn off the battery)

In real life you battery will probably provide between 13-14 volts which decrease your current even more. So as long as all your components on that circuit are rated for 18.4 amps or more then you will be fine. a standard 12v 30Amp relay should do you. Personnaly I like to fit 40Amp ones just in case I want to put more lights in a circuit or put high power bulbs in.

mav

[sean f]

Sorry Sean, Just read your responce again, are you saying that the side light bulb within the crystal hedlamp bowl is ilegal for road use? or were you just refering to additional lights?

Cheers, Jason.

I was refering to the additional lights. Can't see any reason why side light bulbe with in the headlight would cause any problems they wouldn't cause any dazzling of other drivers and are standard fitment on many newer cars.

[FridgeFreezer]

In real life you battery will probably provide between 13-14 volts which decrease your current even more.

Errr, no. You were right about P=I*V, but I=V/R, R stays the same (load, in this case the bulb) so if you increase V, more current will flow, not less. Hence why your bulbs would pop if you connected them to 24V.

[Maverik]

Errr, no. You were right about P=I*V, but I=V/R, R stays the same (load, in this case the bulb) so if you increase V, more current will flow, not less. Hence why your bulbs would pop if you connected them to 24V.

hmm ok,- wednesday isn't a good day for starting bun fights

To do it properly, use both rules which will alow you to verify that your wireing is ok to take what you want to put on/in it.

[Adam001]

As far as bulbs go. At 12V the bulbs will draw less, at 14.4 they will draw more, any more voltage the bulbs will blow. They will output 55W at approx 14.4V. and hence the maximum current. However some electrical equipment will be rated at maximum current at 10.8V then internal voltage regulation above that.

Therefore when specifing current I always take the power of the equipment and the lowest possible voltage of the equipment as then you will be safe regardless. So Maverik is correct in his method as it gives you some slack.

I have plenty of lights on mine, all of which are 55W in pairs so I could power them direct through my 20amp switches, but I use relays as I switch them all to my full beams.

[Guest]

Cheers Guys, I should have split my questions really, one into legality and the other best practice/experience.

I had taken load and wire resistance etc into my calculations when I originally made the original loom and wired them onto a single relay, my question around two relays was really about best practice/experience not physical engineering capabilities.

As I say I have been very disappointed by the output of the previous lights and although measured resistance from negative points, and it is within tolerance, all the joints are soldered and the loom is sealed with heat shrink tube the light output just does not seem great, my final elimination is to change the lamps as the ones fitted are cheap "bolt on bits" units.

However as I will have to strip the loom back and de solder the lights I thought it would be easier just to make a new loom anyway, this time I am going to bring a negative back to the engine bay as well as having negative tabs under the light bolts.

Whilst I am going to the trouble of making a new loom I wondered if it would be worth splitting the loom into two feeds on two relays, would this be better practice especially if I wanted to increase the wattage of the bulbs later.

I have managed to get a set 4 of great quality angel eye lamps from e-bay for very little money I was not really bothered about the "angel eye" bit but thought again if I was going to the trouble of making a new loom would it be legal to wire them up. Clearly the answer to this is no so that will save me a job!!

The second bit of that question was around splitting the switches was again aimed around experience not capabilities as they will be two circuits up to the relays, should I just complete the job and put them on two switches?

Cheers, Jason.