Off-road lights with stock alternator

I want to add some off road lights to my truck. I would like to do one of these setups:

4 55w on roof rack, 2 100w on front bumper
or
4 55w on roof rack, 2 55w on front bumper

Would it be possible to run either of these setups with the stock alternator?
Would I need a new battery?

I have HID headlights and would like to do HID fogs in the future as well.

 

[mechjames]

I think it should be alright. I run dual amplifier's in my truck. One's a 400W and ones a 700W i believe. I haven't had any trouble. I also have hid's in my headlights as well. The only thing is, the battery voltage drops a LITTLE when the heater motor is on.Thats it. Even with eveything running.

 

[little x]

Your truck has a 130 amp alternator. Each light will draw its number of watts/12 in amps. So one 100 watt light needs (100/12 = 8.33 amps).
So 4 55 watt lights and 2 100 watt lights totals 420 watts. 420/12 = 35 amps
Your truck should be able to handle the extra electric load with out a problem.

 

[corkey]

i run 3 55 w on the roof rack , and 2 55w on the front bumper.
Witht the headlights on, and the lights all on, i can even run my stereo with a big kenwood amp and the factory amp at a decent volume on the highway no problem, and off road it seems okay , even with the heat on ,
mine is a 96 xl , with the stock alternator,, and an Optima battery , ,

 

[2000limitedx]

Sweet thanks guys! Thats what I needed to know.

 

[Sandy]

Check the alternator output in the book and see if it does put out 130 amps.
If so then there should be no problem, just watch the volt meter if it starts to drop while you are running the lights and continues to drop then you may need to replace the alternator or maybe even a new battery.

How R U hooking up the lights ?

More than one relay or on all at once ?

 

[corkey]

mine has 2 relays, and 2 switches,

 

[2000limitedx]

Check the alternator output in the book and see if it does put out 130 amps.
If so then there should be no problem, just watch the volt meter if it starts to drop while you are running the lights and continues to drop then you may need to replace the alternator or maybe even a new battery.

How R U hooking up the lights ?

More than one relay or on all at once ?

I haven't bought them yet. I was just wanting to see if it would work before I do. I was planning on using 1 relay per pair, and 2 switches. Is this a good idea?

 

[Sandy]

To me , yes it is a plan.
One of the switches will work two relays, it will work OK ?

The 55 watt lights on the roof, ONLY MY OPINION, just short of useless, unless they are pencil beams; driving lights or flood only light up the hood.

Relays should be the 30 amp automotive type, with one pin 87 no 87a; unless you are getting creative and want something to turn on when the lights are out.
Always use a heavier gauge wire than you need, i.e. if the circuit calls for 15 amps, where 14 ga wire will get you by, use 12 ga or even 10-ga like I do.
If you use 10-ga wire for the power you can always add higher output lights (up to 300 watts per pair) at a later data and all you need to do is change the fuses.

Make sure to use a fuse in the power line from the battery to pin 30 on the relays.
Make sure the fuse is no larger than the smallest component's draw, in your case 2-55w lights draw just under 10 amps so the fuse can be 15 or 20 amps per set of 55 watt lights.
The set of 100 watt lights will draw over 15 amps so a 20 or 25 amp fuse is needed.
The over all process is simple, just do it in steps.

My first truck had four 150 watt lights on the roof, OK but too much overhead, too much glare on the hood, not really for the way I drove just for looks.
My next truck had four 150 watt lights on the front Bumper almost to the hood level, two pencil beams on the outside and two flood on the inside, those worked the best.
Two switches, two relays and two power lines with separate fuses.

luck,

 

[storlied]

I've been thinking about some serious lighting... 4 100w lights up on the roof, and 4 100w lights in front?.. Eh eh?.. So could the alternator handle it considering that dude up there has like an 800w amp??? Is the math still the same?

800w/12v=66.6amps

 

[Bill Kemp]

Only way to tell is to do it. Will probably come close to stalling the truck at idle with headlights & heater & stereo going but should be all right going down the road.

 

[mechjames]

I've been thinking about some serious lighting... 4 100w lights up on the roof, and 4 100w lights in front?.. Eh eh?.. So could the alternator handle it considering that dude up there has like an 800w amp??? Is the math still the same?

800w/12v=66.6amps

you'll be fine. 66 amps isn't much on the battery. just make sure that you have an inline fuse when u wire it in, because 66 amps could light the wire on fire.


your alternator is probably around 100 amps while it running. battery has a lot more. worst case scenario, you'll lose alternator output while idling, like a drop down to 12.8 or 13.2 volts, instead of the 14+ volts the alternator will increase the voltage to while driving. truck will still run fine, but you'll notice a little dimming and the volt gage drop down a bit. its still within normal range. I get this when my heater fan is on as well, it pulls a lot of amperage.

 

[Sandy]

I've been thinking about some serious lighting... 4 100w lights up on the roof, and 4 100w lights in front?.. Eh eh?.. So could the alternator handle it considering that dude up there has like an 800w amp??? Is the math still the same?

800w/12v=66.6amps

OK Storlied, I'll say something, even though this is 2000limitedx's thread.
First any load over the stock electrical systems in a vehicle is overloading the latest systems but a certain amount is doable.
To answer your question the best I can NO, Not a Chance... unless your alternator is a HD 130 amp setup.
Put on teh setup you want for lights, set them up using four circuits, use them as you like watching where the volts meter goes as you turn them on.
If the stock alternator holds up and the voltage remains at 14+ volts then it may work out if not start replacing; battery last.

My basic rule of thumb is, two lights per relay, so if you have 2 x 100 watts = 200 watts - 17 amps per pair of lights.

So for each pair of 100 watt lights you will need one 30 amp automotive relay with four pins, numbered 30, 85, 86, and 87.
Note: Stay away from the relay with 87a contacts, mainly because when the circuit is off pin 87a will be live, that is unless you have a need for it.

That will be four relays for you storlied... how you switch these relay is up to you, four switches each switch controlling a set of lights or two switches or even one but the more switches the more control of the lighting you have.

IMHO, 17 amps/pair is too much for 16 ga wire and 14 ga will handle 15 amps safely but 12 ga would be my choice, it will handle 20 + amps so the fused power wire from the battery to pin 30 and then from pin 87 to the lights needs to be 12 gauge wire and fused for 20/25 amps.

IMHO this is the basic safety setup, no overloading of the circuits, extra circuits to make sure if one goes out the others will still work and get you home.

Are there other ways to do this hook up, yes, but this is my way. Extra circuits and oversized wire makes for the best all around setups.

Luck,

 

[storlied]

Honestly, at this point... I'm thinking about having all 8 of my lights.. (hell, I might just stick with 4 in front on a prerunner bar).. I'm thinking about keeping all the lights at 55w to take a crap load of.. lol.. load off the system.. it'll be two typical Hella wiring harnesses (or 4) with thicker wire only from the battery to the relay.. which makes logical sense to me.. no need to have thicker wire anywhere else.. specially when the system is setup the way it was designed....... Idk.. I'll figure something out...

is 100w REALLY that much better than 55w? I noticed a brighter light but... idk... I'm not so sure it's worth the extra load on my system.

My current system is running Very well... it's pretty much two stock systems... (minus the 100w in the hella's.. which I MIGHT put down to 55w again....)

I guess ultimately what I'm going to do is going to depend on what fits on the lightbar and how well that works out....

 

[Bill Kemp]

IMHO yes it is. Only about twice as much light as a 55 watt system.
But, the question is what are you going to use it for???
I dont notice much difference in 100 watt driving lights and the 130watt bulbs. (I use the 130 bulbs anyway)
But, for the fog lights I seem to notice a really big/good difference between 55 and 100 watt bulbs. I use nothing but 100 W bulbs in the fogs. Aimed correctly they bother no oncomming drivers but they sure illuminate the areas your headkights dont.

For a one word answer....Yes.

 

[storlied]

Hm, I just checked out my 500FF (with 100w) in it, and powered a 1000FF light (55w).. the 1000FF looked a lot brighter..

 

[Bill Kemp]

As far as I know (not far) Hella doesnt make a 500FF. The Hella 500s are old tech. and use the lense to direct the light. Which sucks up light while directing it.
The Hella FF is a clear lense and the light is directed by the reflector which is a much more officiant way of directing the light beams and therefore puts out more light. Not to mention that the 1000FF is a bigger light and bigger is usually always better.

 

[storlied]

Hella sure does make a 500FF, they converted all those series over to FF... the 500 and 550 was just the beginning.

I might end up using nothing but 1000's on the truck...

I wish I could find a good comparison of each.
The 1000's, I've seen more of a wide spread of light than with the pencil beam 500s... would that mean the 1000s aren't gonna compare to the 500s as far as distance goes??


Can anyone find any type of comparison of these lights?

 

[Sandy]

As Bill stated, determine what you really want the lights for... ?

If you need the extra lighting then the 100 watt lights are the way to go BUT if you are just looking for a good look (I know that one) the 55 watters will do.

Just buy a light that fits what you want the package to look like and mount them.

Then as I said before wire them to run on more than one circuit and switch and you can alter the look as you want.

And by the way... 2000limitedx how is your project turning out ?

 

[storlied]

I have a mix of needing to see my sides, and far. We have a lot of moose around here... and outta town.. really long roads..

Are the 1000s better than the 500s in every aspect? Or is it a completely different beam pattern? I'm not finding anything good for comparisons.