# Power consumption for extra Spot lamps



## Trance (Mar 2, 2007)

I am looking to add a set of 9" Hella spot lamps to the front of the new Ducato. The bulbs i would like to add are 130 watt, i know that the limit for the driving lamps is 55 watt but these spots will be through the full beam, therefore, i feel that this will not be dangerous to other drivers. I am trying to work out loads on my alternator and was looking for a wee bit of advice/help with the power requirements. Working my load ratings out as follows: 

130 watt bulbs will draw 10.83 amps (say 11 amps) x2 = 22 amps.
I have also added some small driving lamps 55 watt drawing 4.58 amps (say 5 amps) x2 = 10 amps.

In total with the 2 extra sets of lights running would equal about 32 amps. Now my question is this, is this too much extra load for my alternator?. I am not sure what these alternators are running are they 50 amps/60 amps?. Would the load be too much?. Bearing in mind my main headlights would also be running about 10 amps. 

Last question with the 9 " spots running on 22 amps would a 25 amp fuse be too small, would i have to go to 30 amps?

Thanks in advance

Gregg


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## DABurleigh (May 9, 2005)

I think it would be easier to remove your sunglasses 

Your alternator will cope, most are 90A minimum, but be aware they certainly are not designed to deliver their rated output continuously, and, of course, you may have wipers, blower, etc as well.

And if you want to avoid mayhem around you, I hope you dip quicker and more reliably than many drivers I seem to encounter :evil: :evil: 

Dave


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## 100004 (Jul 12, 2006)

Irrespective of whether they are main beam or not, I'm pretty sure that 55w is the legal max. Personally, I would just use the Phillips extra bulbs.as they are damned good. The alternator should stand it, but you could go up to 85amp just to be on the safe side. H


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## Trance (Mar 2, 2007)

Yes my dipping skills are second to none!.  The reason why i need so much light is i drive alot of back roads at night in winter with the van, and i have had too many close encounters with deer!. Thanks for the reply, 90 amps would work fine then ;D


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## geraldandannie (Jun 4, 2006)

And I would think a 25A fuse would be too small - there will be a short surge when you turn the things on, which will be enough to blow the fuse.

Just make sure your wiring is rated higher than the fuse, although from the sound of it, you probably would do this anyway.

Incidentally, I skipped around Google a bit, and kept finding references to 65A / 55A alternators, although these were on older vans, I think. Can't seem to find info on the Fiat site for current Ducatos :roll: 

Gerald


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## Trance (Mar 2, 2007)

Would the 25 amp fuse be o.k with 22 amps running load?


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## geraldandannie (Jun 4, 2006)

Trance said:


> Would the 25 amp fuse be o.k with 22 amps running load?


Best thing to do is try it. I would have thought it was too close - the problem is that you might be plunged into (relative) darkness if it blows as you're driving along. I'd rather be safe than sorry.

Gerald


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## Trance (Mar 2, 2007)

Go the 30 amp fuse me thinks then.


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## DJP (May 9, 2005)

If you are wiring it in directly into the vehicle system so the lamps come on on main beam, then I would most certainly check with base vehicle manufacturer to ensure wiring has capacity to cope with extra amps. Also consider using a 30 amp relay. the alternator output will not be a problem. Better still seek professional advice from an auto electrician. 
Dennis


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## 88781 (May 9, 2005)

Better to wire and switch them independantly from the vehicle wiring. Instructions, relays etc. should be in the box. :wink: 

MnD


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## DJP (May 9, 2005)

> Better to wire and switch them independantly from the vehicle wiring. Instructions, relays etc. should be in the box.


Not many come withem in the box, however you can buy a wiring kit seperately. Wiring them in seperately is the easy, safest way but if using the at the same time as main beam lights, it is another switch to turn off QUICKLY.


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## Trance (Mar 2, 2007)

The only connection to the vehicle wiring would be from the existing high beam which only acts as a signal wire to the relay. The wiring to the rest of the system would be through 4mm2 cable and the relay i have up'd to 40 amp. I am ssuming from this that there would be no extra load on the existing wiring just my new cabling. 

gregg


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## Trance (Mar 2, 2007)

Wiring diagram example which i am going to incorporate.

http://www.hilux4x4.co.za/wire_spotlights/index.php

Obviously fuse size will be 30 amp, bulbs 130 watt and 40 amp relay, cabling 4 mm2, I think i have thought of everything!


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## johng1974 (Jan 17, 2007)

doing mine tomorrow too 

although this is to replace manufacturers wiring as my Citroen (car) looses about 15% brightness because of thin OE wires etc..

So going to wire main and dip circuits directly with thicker wire etc. i,e 2 relays, 4 fuses etc etc

good luck, 
John


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## Trance (Mar 2, 2007)

What size of cabling should be used for earthing?. As i am using 4mm2 for positive cabling, what size would be best for earthing?


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## clodhopper2006 (Aug 13, 2006)

Trance said:


> What size of cabling should be used for earthing?. As i am using 4mm2 for positive cabling, what size would be best for earthing?


The same 4mm2. Current flow is constant throughout the circuit


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## johng1974 (Jan 17, 2007)

Thats strange, when I did a test on my headlights, brightness was much improved with a larger x section feed, using the original earth or a bigger earth made no [more] difference to brightness..

But thanks CH


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## Trance (Mar 2, 2007)

Would the current flow be the same at Pole 85 of the relay?. Would the switch on this pole (earthing) have to be rated above the value of the spot lamps? Would i need a 30 amp switch in otherwords?


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## pippin (Nov 15, 2007)

Will your vehicle pass the MOT with all this candlepower added?

Or satisfy the policeman who thinks you are a boy racer and pulls you over?


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## Trance (Mar 2, 2007)

pippin said:


> Will your vehicle pass the MOT with all this candlepower added?
> 
> Or satisfy the policeman who thinks you are a boy racer and pulls you over?


Thanks for your concern pippin, as i have said these lights are wired into my full beam and Mr plod will not get to see them, no-one apart from me will. They will not present a danger, and as far as i am aware there is no law on this for full beam , just headlights.


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## pippin (Nov 15, 2007)

Not quite certain of the distinction you are making between "headlights" and "full beam".

If there is a legal limit on the wattage for headlamps on full beam then surely there is a legal limit on the wattage for spotlights when used on full beam with your headlamps.

Or are you going to use these only when "off road" (nudge nudge, wink wink)?

Hopefully someone else will come up with the definitive answer - I wouldn't want you to go to all this work and expense and then find they are illegal to use.


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## Trance (Mar 2, 2007)

I feel the 55 watt bulbs do not offer much of an advantage in these size of spots. I am curious, if there was limits in "full beam" lighting why do lorry drivers in some cases have up to 6 of these lights on there roof. That is a fair bit more light than i am planning on using. I mean what kind of limits are there then?. A lorry driver, although larger in every way to cars/vans will still cause the same 'dazzlement' to each and every vehicle on the road. The point i am making is they will be used sensibly, i am not a boy racer i am just being extra safe as i have had too many close encounters with deer in the past. With the lights being used sensibly there will be very little danger to other drivers and no reason for Mr plod to have an opportunity to stop me. I think you will probably find there is a grey area here with the distinction between headlights and full beam. If push does come to shove, i will change the bulbs and fuses to the correct replacements.


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## Autoquest (May 16, 2007)

I did a similar upgrade on my Triumph Stag a few years ago - The whole point of the relay is that it will switch a high power load with a low power switch - Otherwise the cabling behind the dash would be pretty impressive  

86 & 85 are part of the low power circuit, hence the one amp fuse, and merely switch the coil in the relay to energise the high power circuit through 30 and 87, which should consist of some mighty thick wire. 

Make sure that 30 Amp fuse is fitted close to the battery.

You might find that the pattern of light is not that useful to you when you switch them on though... a bit akin to having to having searchlights pointing forwards with a very narrow spot beam - As long as the deer is within the, lets say, six foot circle of light? then all will be well but if the deer is outside that six foot circle you still won't see it as the beam is so concentrated with no spread.

Nice project though


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## DABurleigh (May 9, 2005)

Legal limit:
"However it's important to not fit headlamp bulbs that exceed the legal output limit, which is 60 watts for the main beam and 55 watts for the lower (dipped) beam. Headlamp bulbs with a higher wattage can only be fitted for off-road use only."

Dave


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## Trance (Mar 2, 2007)

Many thanks for the info Autoquest. Yes i was aware the beams would be narrow on the spots, thats why i have also added driving lamps, i am hoping that this setup is going to help a considerable amount. 
Dave, yes, I was kinda thinking that it would be bending the rules somewhat, just could not find a reference to full beam. Curious that you can add say 5 spots to a lorry at 55 watt each giving a total of 275 watts and not 2 at 130 giving 260 watts?. I suppose that the light is not so concentrated at one spot of light?.


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