strikechords

Alright so I think my jeep had the plain factory rectangle fogs, it has the stock switch on the dash and when i bought it the wires were hangin from behind the front bumper. on monday i found some off brand 130 watt driving/fog lights that i wanna put on there. my let me drive his car for a while before i got my jeep and it had fog lights, they were really nice to have, so i wanted to get some for my jeep. i got the 6in diameter ones.... ok, so i might have bought them partially becuase they came with some oldschool vinyl KC daylighter covers... but anyways. i had two questions: 1: are these things even legal? my dads been saying im gonna get a ticket for them, but then again he says that about everything. i did try looking up state laws and stuff and alls i cold find was only use them in rain/snow/fog or unclear conditions. question 2: i dont suppose i can just wire these up to the stock wires? that would be nice, but i figured these were pretty much the same price as 55 watt sets and it'd be nice for having better visibility in the awesome wisconsin winters and in the dirt. any info will help!! thanks guys

TrekkerJmm

AFAIK 130 watt lights are just for off road use and are supposed to be covered at all times in certain states. I believe they are too bright to drive with on normal roads but I'm sure you will get some more opinions here. BTW I use 55 watt driving lights and ppl high beam me to shut them off all the time...Tj

Abovetimberline

I am sure someone on here can tell you,but what I would do is look at a similar set at the auto store and see what the instructions say.

mike37

if they have a

SAE and/or DOT number you should be OK but use of the lights are still restricted
they must be lower than the head lights and aimed so the glare is not effecting oncoming drivers and cant be used with the hi beams on

thats just a general rule some stats will be more restrictive that others

5-90

I would not recommend the use of 130W bulbs in "fog" lamps - too bright.

Use an amber lense and/or reflector bowl, and I'd go with 55W max (if you can get down around 40W, all the better.)

The idea of a fog lamp is to actually allow you to see past/through fog - white light will bounce back at you and you can get "white out" from it. The amber colour does a much better job of penetrating fog (and snow and rain) than white does, and won't glare back as badly.

Fog lamps should be mounted at or below the level of your headlamps, and actually aimed so that the beam declines just slightly as it goes forward. Per-Lux makes a very good fog lamp - proper colour, low-power bulb, and they're louvered to cast the light downwards just a bit and help prevent "white out" even more. You can usually find them at places that cater to heavy trucks (Class 4 and up) for a nominal fee - they're the people that use them the most.

strikechords

Update on the fog lights incase anyone was wondering. Went to advance auto or whatever got some Hella H3 Halogen Xenon Blue 55 watt bulbs that fit in the housings I got. The box says DOT Compliant, so im assuming I can use them on the road then, right?? I'm almost done wiring them, whoever had my jeep before me added a security thing and must have took it out, theres a bunch of extra wiring and there wasnt a hot lead going to the fog lights. So hopefully tomorrow I can get them lit up/aim em.

AdidasCJ

Ok 55w "Driving Lights" are the only ones legal to use on streets. Any of the 100w and 130w lights are to bight and are marked for "off Road use only" as they are BRIGHT as all hell. I have 2 KY Daylights with 130w bulbs and they are REALLY freaking bright... also if you put a 130w or even a 100w bulb in a "fog light" housing it has the chance to melt the housing. If you have like the aftermarket KC or even Hella housings they are made to withstand the higher heat. Also 130w may not be safe to run with stock gauge wiring....

4.3L XJ

That is true. You should use a 30 amp relay and #10 wiring

5-90

1) OEMR wiring is selected for 55W bulbs - max. Build new harness and use relays (and fuse it!) to go any higher.

2) Blue is just as bad for fog lamps as white - that's why I specified amber tint. There's a good reason for this - I've seen kids with those "bloo" headlamps get flared out in fog and try to follow me (since I turn off my 90W Super White low beams and use my 55W Amber 550s) until I pull over - if they're not properly equipped for weather, it's not my fault. And, they invariably try to use full beams behind me - which just makes me want them to get into a wreck.

Bear in mind that the purpose of a "fog lamp" differs mightily from a "driving lamp" (and I'm fully aware of this - I have both on my rig.)

A fog lamp is designed to give a low, wide beam to maximise visibility. The better ones have an amber-tinted lense and/or reflector bowl (so you won't have to go look for amber-sleeved or -coloured bulbs) to let them cut through glare and flare.

A driving lamp is designed to give a tightly-focussed beam to improve visual range. Driving lamps are invariably clear/white, and a good driving lamp will respond well to a high-powered bulb (I turn mine on when in the mountains - with their 100W bulbs. Judicious use and aiming is indicated with high-powered bulbs, that's why I've been able to run E-codes with 90/130W Super White bulbs for years without being bothered by the Law.)

"East is east and West is west and ne'er the twain shall meet." A fog lamp is fundamentally different from a driving lamp, and neither should be used as the other. Period. It would be akin to using a hammer to drive a screw - you can try, and it might even work for a little bit, but it's an inappropriate use of tool and/or fastener.

If you want driving lamps, get driving lamps, and put the high-powered bulb in there. If you want fog lamps, buy proper fog lamps, and put a low-powered bulb in there.

My lighting:
- Hella E-code headlamp bowls with 90W/130W Hella Super White bulbs, and a homemade relay harness.
- Hella 550 Driving lamps with 100W Super White H3 bulbs
- Hella 550 Fog lamps with 55W Yellow Star H3 bulbs (complements amber tint of bowl/lense neatly.)
- 50W 1156 bulbs in taillamps (improves visibility of rear-end in fog.)
- 50W 1156 bulbs in turn indicators (don't tell me you didn't see my signal. Operation verified monthly.)
- PAR34 floodlamps slaved to reverse lamps (via relay) with override ON and override OFF switches (make useful backing lamps, also useful working lamps.)
- PAR34 lamps on front bumper on independent switch (primarily as roadside working lamps. I stop on the side of the road to help people a lot, and I want to make sure people know I'm there!)

I've got some spare taillamp assemblies, and I've recently scored a batch of high-powered LEDs, so I'll probably stomp something up as an effective replacement - while the 50W bulbs are workable, I'm worried about heat (although the 50W incandescents seem to last longer than the 50W halogens did - they don't get quite as hot.)

BeaglesXJ

ok 5-90 since you seem to know alot about lights i guess ill ask you this. what about long range lights? im gonna get 4 130 watt kc daylighters and they are the long range light. so what kind of wiring would i need to run these and are they any good? im mainly going to use these for shining deer in the big fields behid my house and i want to be able to see a bit closer range too then just from a distance.

5-90

Wire size is determined by the current to be transmitted, and how far it needs to go.

Lamps in sets are typically wired in parallel, so that each lamp gets the full 12VDC supply. This makes it easier to determine current - figure the current requirement for a single lamp, and then double it (for two lamps. For three lamps, treble it. You get the idea.)

You'll find Ohm's Law (E=I*R) and Watt's Law (P=I*E) to be very useful for electrical issues - voltage, current, resistance, and power are all mathematically related. The equations may be combined or rearranged using standard rules of algebra.

We need to know what your lamps will draw, in terms of current. Therefore:

2 * 130W lamp = 260W.
260W/12VDC = 21-2/3A

(NB: Actual current will be slightly lower, as actual opeating voltage is slightly higher than the nominal 12.0VDC. It's usually closer to 13.6VDC or so. However, using 12.0VDC allows you to have an "inbuilt" safety factor of about ten percent - and it's not going to cause you any trouble. So, get in the habit of using the nominal 12VDC...)

You now know that your power source will need to be fused for 25A (the next higher fuse rating available) and you'll need a relay that is good for a minimum of 25A (the standard DIN relay - the little 1" cube that can be found all over the XJ in the first place - is typically good for 30A. Some versions are rated for 40A - but don't try to push more than 30A through the relay unless you know that it's a 40A version! Period.)

Using the figure generated (~22A) and figuring less than twenty-five feet for a round trip (Ampacity charts tend to start with a length of 25 feet...) you're looking at using wire of at least 10AWG in size (if it were "open air" wiring, you could use 12AWG - but figure that you're going to have a problem with heat dissipation.)

Why is heat a factor? Current transfer = heat, and heat = bad. Larger wire has less internal resistance, and therefore will generate less heat than a smaller wire, assuming carriage of the same current.

Use 10/3 SJOOW wiring for simplicity (three conductors in a single jacket,) ease of handling (it's fine-strand cable,) and safety (SJOOW is oil-, grease-, and water-resistant.) You should be able to find SJOOW at your local hardware store without too much trouble - but make sure it's SJOOW! It should have a black rubber jacket, and SJOOW will be clearly printed on it. Do not use SOOW - it's just water-resistant, and the oil and grease underhood will degrade the insulation!

As far as the lamps proper, KC isn't a bad brand. You can mount them on the bumper or on a roof bar - if they're on a bumper, aim them about two degrees down from horizontal (WRT the static ground line.) If they go on the roof, drop them about five degrees. Stick to a proper white bulb - like the Hella Super White - for best visibility (I've heard the arguments on using the "Bloo" HID-like bulbs. I find better visibility using the Super White bulbs - or equivalent, as long as they give a white light.)

The "Long Range" lamp assembly should have a fairly tightly-focussed beam, which will give you downrange visibility.

As far as fog lamps, I see two ways to use these:

1) Use a clear lense, white bowl, and white bulb. This would be used for a short-range "fill-in" lamp, and you can effectively run any power of bulb that the enclosure can safely handle. Do not use in foul weather! Aim 1-2 degrees below horizontal, on the bumper.

2) Use an amber lense, amber bowl, and yellow-emitting bulb (like the Hella Yellow Star.) Use a maximum of a 55W bulb - I find 30W to be about ideal. Aim dead-on horizontal, on the bumper. These can be used to increase visibility in foul weather (fog/rain/snow) with good results. You will definitely want an amber/yellow light - as the colour will reduce glare and flare (ever turn on a bright white lamp in a snowstorm? It's like being inside a ping-pong ball...) Mounting them on the bumper and aiming them dead level will also help keep you from getting "flared out" by your lamps by keeping them below your line of vision, and the wide dispersion pattern actually reduces backscatter of light (which inhibits visibility for you.)

A true "fog lamp" will have a wide beam pattern - something like 80-130* horizontally, and 15-20* vertically (with a fairly shart top cut-off.) A "long range" or "driving" lamp can also be called "pencil beam" - you're looking at a dispersion of something like 10-15* (conic beam) and a range of 10,000-12,000 feet. The cutoff won't be quite as sharp.

As far as wiring ampacity, charts can be found online. Be sure to use a chart rated for DC current or single-phase AC, and not multi-phase industrial wiring (the rules are different.)

fantic238

It doesen't really work like that.

Amber light won't go past/through fog more than the white one. The reason why you see better with amber light is because the human eye retina perceives an object illuminated by yellow light with a higher contrast. The maximum sensitivity occurs around 555 nm (540 THz in frequency), corresponding to yellow/green light.
You won't see farther, but you'll see the objects much more defined with a better sharpness.

BeaglesXJ

cool. thanks 5-90

5-90

Hm. So, "correct conclusion, incorrect theory?" Thanks for that, we are always learning something new...

Any thoughts on why you won't "yellow out" with an amber lamp, like you usually "white out" with a white one? I understand what you're saying about visual sensitivity and contrast (which is why NVD displays tend to shades of green, I'm sure,) but I get the feeling that doesn't explain all of it...

fantic238

Ok, i'll try to be less technical as possible so everybody can follow us.

Refraction ("white out") depends on two things: the wavelength (color) of the light emission and the matter it is crossing.

Lets have a close look at matter fog: fog is millions of tiny little water droplets in suspension in air. Another correct description for fog is a cloud on the ground.

Every time light crosses a drop of water, its speed (c) is reduced of 2/3 and when it comes out from the drop it will have only a speed of c/3 to go through the next drop.

The penetration of light through a medium that has refractive index higher than 1 (vacuum) depends only on the light intensity.

The direction of the beam changes everytime it crosses the surface of the drop, one part goes through, one part changes direction (refraction) and one part comes back (reflection).
This phenomena is called light scattering.

Now, in addition to the amount of light that is being scattered in the fog, there is also the light emitted by the fog itself after some electrons of the water have been excited by the absorption of a part of the photons of the light beam.

The average light scattering is defined by the refractive index, a number that tells us how much light is being refracted and how much is being absorbed.
Water has a refraction index of 1.333n at a wavelength of 585 λ (average color "white") and 1.2 at a wavelength of 597λ (yellow).
This means less "white out" with the yellow light, because it refracts less and keeps the beam together, although it won't go further than the white one.

The position of the beam is very important too, like you said. Have you ever noticed that you see better with low beam rather than high? Well the truth is that you don't see better, you just DON'T see the fog above the light beam and it doesn't white out.
I have two 70W H3 yellow fog lights mounted on the roof and they "yellow out".
It is the wrongest place where to mount fog lights (i am conscious, but they look nice together with the other three white ones) because the beam is over your head, and the only thing you see in the fog is your nice and clean hood and a bright yellow supernova above it. If i move those on the bumper i am sure i will not have the supernova effect, but that requires time, a physical quantity that does not appear in my formula at the moment.