High Output Alternators

I will at some time be buying a truck (once i've moved) which will most likely be an '01-03 F-150. i want to add spotlights to both the front and also on the roof, as well as a lightbar. i figure to run between 6 and 8 spotlight and also a lightbar (although it'll rarley be used) i'd need a more powerful alternator to cope with the increased power demand.

what i'd like to know is firstly, will i need a higher output alternator?

also, what kind of output would i need (amperage)?

and finally, if i install a higher-output alternator, will that have any negative effect on the truck when the lights aren't being used? will it cause fuses to blow or cause circuit damage?

Thanks,
Chris.

what will be the total amps of the lights you use? Gotta know that before you can debate on what alternator will work.

There are no disadvantages, assuming that the wire gauges are large enough to handle the added capacity of the alternator. Fortunately, its quite easy to upgrade the alt wire if necessary.

since resistors are the only 100% effiecent devices for energy transfer, and that's all a bulbs is, i'm going to say it's safe to assume that light output is pretty much equal to current demand. (that is right, isn't it?)

i'll have a look and work it out.

not sure what you're getting at, X candlelight power = X watts? Not even close. There are many diferent types of lights that have different levels of efficiency/output per watt.

How can you possibly answer this question if you don't even know what lights, and how many, you plan on using?? Thats like asking how hard it would be to make 200hp with an engine that has unknown cc's and cylinders.

So, Iv got this neck, and I want to make it red.

How much hp will it have, and how much current will my mullet draw?

also, what kind of output would i need (amperage)?

Add up the watts of all of your devices (lights, stereo, fans, EFI etc) and divide by 12 (for a 12v system) to give you a rough idea of amperage.

Then you want to find the rating of the current alternator and compare.


IMO too much light is stupid. You end up blinded by the reflection off roadside signs and going to dip makes it hard for your eyes to adjust.

if it were me, i would figure out the amps needed, then err on the higher side because nobody likes being stranded due to a dead battery...
also, how well and when the alternator is producing power is a consideration too.
a lot of police cars are equipped with alternators that can supply ~80% of total power at idle. they are more expensive, but better (IMO)

not sure what you're getting at, X candlelight power = X watts? Not even close. There are many diferent types of lights that have different levels of efficiency/output per watt.

How can you possibly answer this question if you don't even know what lights, and how many, you plan on using?? Thats like asking how hard it would be to make 200hp with an engine that has unknown cc's and cylinders.

i'm looking at various lights, and choosing the ones i want.

what i was asking was is it correct that power demand is equal to light output.

ie: 8 lights x 100w (100w per light) = 800w (i think this bit is right)

but then is 800w the right demand, or is there something else i've missed out that needs to be accounted in.

i'm looking at various lights, and choosing the ones i want.

what i was asking was is it correct that power demand is equal to light output.

ie: 8 lights x 100w (100w per light) = 800w (i think this bit is right)

but then is 800w the right demand, or is there something else i've missed out that needs to be accounted in.

Watts is power consumption, not light output.
Light output varies hugely when comparing lights of the same power consumption.

i'm looking at various lights, and choosing the ones i want.

what i was asking was is it correct that power demand is equal to light output.

ie: 8 lights x 100w (100w per light) = 800w (i think this bit is right)

but then is 800w the right demand, or is there something else i've missed out that needs to be accounted in.

to put this in perspective: 800w = 67 amps. A stock F150 has 2 stock alternator options, 95 and 115 amps. Now its extremely unlikely the system amperage is only 30 amps, but of course, it depends what you have turned on, such as headlights, blower motor ect.

If you cut it down to 6 100w lights, and used the 115amp alternator, and kept an eye on a volt meter, being careful of what accessories you have on when all the lights are on, you'd probably be fine.

But there's probably upgrade options also

i'm still trying to find the "right" lights, haven't made a final decision yet.

i'm thinking Hella, i know they're good. any other reccomendations?

also, anyone know a good brand for high-output alternators? i'm struggling to find one.

According to Ford literature, the 1997 F-150 4x4's available in the United States all have 130-amp alternators.

might not need to replace it..

Yes... you may not even need to replace it. Also, 100w lights are a bit over the top IMO. Most halogen head light bulbs run at 55w and high beams run at 65w. Obviously you want recreational lighting. Perhaps a couple of 100w lights and a couple of 65-80w lights. My suggestion would be to go look at trucks that already have lights on them and see what they are using. Where I live there are more pick up trucks than probably most anywhere (South Carolina) and everybody has mods... even work trucks are lifted with tires and lights... and yes, the ever present tool box in the back as well. If you research more in depth for which would be the most efficient lights to use let me know because I'm probably going to install some nice fog/driving lights on my Jeep.

If you research more in depth for which would be the most efficient lights to use let me know because I'm probably going to install some nice fog/driving lights on my Jeep.

the 100w was just an example number for ease of showing stuff in calculations.

i'm going to carry on looking into this, i can't offer an post-usage info for a while because the earliest i'll be getting a truck is like august/september (if then, maybe later) and i doubt i'll be getting lights on it for a while after i get it. (money being the deciding factor.)

Oh yeah I know. I meant if you come across some sweet examples of mounted lights on trucks or SUVs post em' up or send a PM. I've been looking a little as well at the Hella lights with the mesh guard around them...

Oh yeah I know. I meant if you come across some sweet examples of mounted lights on trucks or SUVs post em' up or send a PM. I've been looking a little as well at the Hella lights with the mesh guard around them...

will do. i'm mainly thinking of Hella because they have good brand reputation. i'm looking for lightbars meant for things like Sprinters (Dodge in the US, Mercedes-Benz in europe) and euro-style bumper-mount light bars, i'll see if i can buy just the alloy bar and add my own lights.

http://www.kelsa.co.uk/images/products/Sma01med.jpg

That's the kind of thing i want for the bumper.

maybe not that particular one, i'm having trouble finding the manufacturer of the exact one i want. (they're about $800!)

might not need to replace it..

thats only on the 4.2L V6, for some odd reason. Not availible for the 4.6L or 5.4L

only the 4.2-litre had the 130amp alternator?

hooked on phonics? :D

thats what I said....not interchangable with the V8 units

Gah!

oh well, i guess i'll have to get one of there $300 aftermarket ones.

http://www.dun-bri.com/asps/uploads/super/631-1.jpg (http://javascript<b></b>:history.go(-1))

what do you think? :biggrin:

$700 :eek:

Well, a couple of the county sheriff vehicles around here are Jeep Cherokees and they have light bars like that on the roof... but they're blue... LOL

I think I'm going to stick with the bumper mounted style lights with maybe a brush guard. Who knows?

I'm a child...

since i was a kid seeing fire truck and recovery trucks with flashing lights i've wanted to have them on my own vehicle.

i want 4 spotlights on a bar on the front, 4 on the roof with 2 amber beacons and the flashing lightbar. winch on the front with proper bullbars (not this brush guard rubbish) and a top hitch on the back.

2.2 never quite grew up...

You could probably get away with that here in SC and even more maybe... LOL

Florida probably wouldn't be too difficult to get all that either...

The South loves Trucks

sweet...

my friend's old car (volvo staionwagon) had blue flashing lights in the grille, in the sunvisors and strobes in the headlights, as well as a police siren (in Britain the emergency services only use blue lights) and we used to get through traffic using it, pulled people over on motorways. it was so much fun!

i've found some Hella lamps that are Xenon and run at 35w each.

i'm still looking to see if there are better ones, i'm going to contact some companies to find out about their lights bars and what maufacurer supplies the lamps for them.

in the meantime, i'm going to do some design work on the mounting bars.

Personally, I run the six set(Halogen)from dirt-tech, along with four more running on my bull bar skid plate assembly, They light up the desert night like nothing else I've tried.
http://www.dirt-tech.com/

I also run their trailing arms, and their front suspension setup, I am extremely happy with dirt-tech and the fabrication they've done on my '98 F150. Took me a long time to save up the money to get that truck exactly how I wanted it, but it's coming together very nicely, and dirt-tech has helped me out every step of the way.

what i'm thinking of doing (if i can get the different lights in the same housings) is have a mix of fog, driving and pencil beam lights, then i have the narrow-beam long range lights, medium beam medium range lights and the low range wide beam lights, everything covered.

Here is the basic part (which I'm sure you already know): W = V x A. Simply add all the wattage of the lights, divide by 12v and that gives you amps. Most systems actually run at 14v or more, but using 12 will give you a little buffer.

The stuff you might not know... typical stereos use remarkably little. Most factory head units put out 13-25 clean watts x 4 channels, but that 25w is only during really peak hits. That's what the battery is for. The teeny bit of draw you take from the battery is replaced in seconds from a 40A alternator. Even using 25w continuous is a safe bet on a factory stereo. If you have amps added to your system, use RMS to determine draw.

A typical EFI engine will draw between 10-15 amps to run. That includes the fuel pump and everything to run the engine
Add 5w for each running lamp
Add 7w for each brake lamp and turn lamp
Add 10w for each backup light

Now, since you NEVER have a situation where all of this is happening at once, multiply your result by .75 and calculate amperage. Running too many amps is not good. Its fine 90% of the time, but the first time you run the battery dead and get a jump start, that alternator is operating at peak output for a half hour or so. Asking more from your alternator than its designed to make will dramatically shorten its life. If that output you seek is available as a factory option, you're fine. If its not and you have to get an aftermarket hi-amp that is based on the same case, avoid it. It'll fry. The factory does a pretty good job of making as much amperage as they reliably can from a particular design. Just because the aftermarket can make more doesn't mean its good.