By on December 7, 2018

led lights

Sajeev writes:

Apparently the ears of noted lighting consultant Daniel Stern begin to burn whenever Piston Slap discusses lighting upgrades. While I gave an analysis of the current LED-landscape to the best of my knowledge, I am honored to publish his insights on Jeep JK headlight upgrades.

And those of us with old-school halogen reflectors get a little feedback, too. Stick around for that.  

Daniel Stern answers:

Like their predecessor “HID kits,” today’s “LED bulb conversions” now flooding the market are not a legitimate, effective, safe, or legal product. No matter whose name is on them, these are not capable of producing light in the right pattern for the lamp’s optics to work; you get a random spray of unfocused light instead of a beam pattern.

But there’s a number of engineered LED headlamps on the market — they range in quality and performance from pathetic to excellent. The 701C from Peterson (in Peterson or Sylvania Zevo packaging — same lamp) is good. The Truck-Lite unit is good, but the king daddy of them all is the 8700 Evolution-J from JW Speaker: these units are plug-and-play in the JK (’07+) Wranglers. With any of the other LED headlamps worth considering you will need anti-flicker/adapters pigtails.

None of the LED headlamps linked here is an advisable choice if you do a lot of wintertime driving with heavy snow and slush; the LED headlamp lenses run cold so snow and ice can build up on them instead of melting off like they do from a warm halogen or BiXenon lamp lens. There is a heated-lens versions of the Truck-Lite lamp and there’s now a heated-lens version of the JW Speaker lamp as well. No heated-lens version of the JK-specific Evo-J lamps, and you’ll need those anti-flicker/adapter pigtails.

There’s also the factory-optional LED headlamp assemblies, but it’s tough to see them as cost-effective: they’re very expensive, their performance isn’t better than the lamps listed above, and they have no lens heater.

About Lamp Aim:

Lamp aim is by far the main thing that determines how well you can (or can’t) see at night with any given set of lamps, so this is crucial: you will need to see to it that the lamps are aimed carefully and correctly with an optical aiming machine per the “VOL” instructions here (unless you install the Peterson or Truck-Lite LEDs, then the correct setting is “VOR”). It can be difficult to find a shop that has (and uses) an optical aiming machine; keep calling around until you get the right answer. “We shine them on a wall/on a screen” is the wrong answer. To get an idea of what a proper lamp aim job looks like, see this VW document.

US/Canada-market JK Wranglers do not have a provision for adjustment of the horizontal (left/right) aim of the headlamps, only for the vertical (up/down). At least in theory this is fine; the horizontal aim is fixed at straight ahead, which is correct.

However, some individuals may need or want to alter the horizontal aim. To add horizontal aim adjustability, you will need two Mopar part number 5507 8114AA (Screw, headlamp horizontal) which should cost only around $5 from any Chrysler/Dodge/Jeep/Ram dealer. To install them, remove the grille and headlight assembly. Carefully remove the black headlamp mount ring/bucket by pulling straight out. Unscrew the pivot stud, thread in the new adjustment screw, push the ring back on, and put the light back in. Then you will have to carefully aim the headlamps not only vertically but also horizontally, keeping in mind headlamp aim is not subject to opinions or preferences; there really is a correct setting for a given kind of headlamp at a given mount height.

If your JK has the daytime running light function enabled (mandatorily in Canada, optionally in the States), and you’re installing anything other than the JW Speaker Evo-J lamps, you will need to rework the daytime running light function to move it off the headlamps — a dealer service department must de-activate the DRLs with their diagnostic computer interface, or you can do it yourself with a device called a ProCal. If you don’t do this one way or the other, the DRLs will operate in an unsafe and illegal manner until the LEDs cook to death (and they will). Why? Because the DRL function runs the headlamps at reduced voltage. This is not safely compatible with LED headlamps that haven’t been specifically designed for it.

Daytime running lights *do* significantly reduce your risk of being in a crash during the daytime, and are required equipment in Canada, throughout Europe, and in a large and growing number of other countries throughout the world because they are a very cost-effective safety device (i.e., they work). The ProCal dingus lets you move the DRL function to the front turn signals, or if you don’t wish to buy a $200 widget you won’t use much, you can add turn signal DRLs, which comply with US and Canadian Motor Vehicle Safety Standards and are approved in all states, provinces, and territories, with a standalone module.

(This is where Sajeev asked Daniel about future LED replacements for the OG 9004 bulb in his beloved 1980s Aero-Fords, like this Mark VII GTC Stage I)1987 Lincoln Mark VII GTC, Image: © 2018 Sajeev Mehta/The Truth About Cars

[That is] Overwhelmingly unlikely to ever happen.

We’re starting to begin to approach getting close on the single-axial-filament types (9005, 9006, H7, H11…), and there’s some promise on the dual-axial-filament types (H4, 9007, H13…) but it is effectively impossible to do it with twin transverse filaments (9004). That’s because the low beam filament is both aft and above the high beam filament. You could make a board with its flat surfaces facing up and down, with its LED emitters in transverse rows one ahead of the other, but that wouldn’t address the “above” aspect.

[Image: Shutterstock user Oleksiy Mark,© 2018 Sajeev Mehta/The Truth About Cars]

Send your queries to [email protected]com. Spare no details and ask for a speedy resolution if you’re in a hurry…but be realistic, and use your make/model specific forums instead of TTAC for more timely advice. 

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31 Comments on “Piston Slap: JK-ing Around With LED Headlight Upgrades? (PART II)...”

  • avatar


    I’m tired of answering questions on the forum regarding headlight conversion kits for a Ford Fusion. I always say buy a car that already has factory HID (aka Lincoln MkZephyr) or LED headlights and don’t blind others with a cheap knock-offs.

    Do you have any comparable to this article suggestions for a Ford Fusion?


  • avatar

    Jebus, this is SO simple, don’t do anything with your headlights, legal or not, that would cause trouble for oncoming drivers ability to see as you would not want, in turn, to be blinded by them. What is the problem?

  • avatar

    Might be a future business for a factory reproduction part company. Aftermarket drop in whole headlight kits. This would eliminate the issue with the casing designed for the halogen bulb because it would replace the whole casing. Automated production / manufacturing technology should keep production costs low and you start with cars that people tend to modify then spread out. Classics, ect.

    • 0 avatar

      This is already a business.

      • 0 avatar

        The Retrofit Source is run by clowns who have made a killing selling cheap Chinese crap to people desiring a headlight “upgrade.” They openly flaunt the laws and regulations.

        How do they market their “upgrades”? They say things like, oh, this item actually EXCEEDED the intensity limits at certain test points in its beam. But screw regulations, because we’re gonna sell it anyway since it’s extra INTENSE, laws and regulations be damned!

        They pretend to just be a reseller of a high end aftermarket brand known as “Morimoto,” which is supposed to sound Japanese, but in reality, is just a name slapped on some cheap Chinese junk. You can go to their home base at HID Planet (forum) and read about the countless number of people complaining about how their “Morimoto” HID ballast stopped working, or how their projector solenoids get stuck, or how their bulbs burned out prematurely, etc.

        People like Matt Kossoff, the founder of TRS and “Morimoto,” deserve to be jailed and fined millions of dollars for the amount of money they made peddling fraudulent products. I mean, he comes out and says it himself: Morimoto products DO NOT meet regulations but that’s a SELLING POINT. I don’t know how else to put it, but he’s introducing fraudulent, unsafe products into interstate commerce. The man needs some time alone to think about what he’s done having 1000s of people bake open their stock headlamps to transplant in some cheap Chinese parts that may or may not be an upgrade. Headlamps are responsible for not only your safety but the safety of everyone else on the road. They aren’t meant to be modified willy-nilly. Only considered modifications recommended by experts, such as Dan Stern, are appropriate.

  • avatar

    I looked on the Sylvania Zevo and Truck-Lite websites. It would sure be nice if they offered a 5.75″ round LED bulb similar to their 7″ bulb, for those of use with older vehicles using quad round headlights. I guess there’s a larger market for the 7″ ones though, since they can be used in modern Jeep Wranglers.

  • avatar

    Do I spy a Conti Mark II in the Mehta collection?

  • avatar

    Best thing about Jeep LED headlights? Perfectly fit into H2 Hummer headlight slots.

  • avatar

    It’s too bad those “king daddy” JW speaker ones (and all the knockoffs) are stupid as hell looking.

  • avatar

    So when you swap your incandescent for LEDs in your house, you save on energy costs. Aside from better lighting, where do those energy savings manifest in the car? I can’t imagine you would be getting better fuel economy, so what is saving energy?

    BTW, I love my LEDs on my Mazda3. I don’t think I could ever go back to non-LED headlights at this point, so don’t think this question is hating on them. Just curious and you all seem like the experts.

    • 0 avatar

      Well the power to run the headlights has to come from somewhere and in the case of a car that is the alternator. The energy required to turn the alternator is proportional to the current it is producing. Lower the current it is producing and it will reduce the power needed to turn it. So yes it will increase the fuel economy, however the change will be so small that it won’t be detectable with the divide the miles driven by the amount to refill the tank method.

      • 0 avatar

        I remember reading an article that calculated that a car with incandescent DRL would use an extra tank of gas over 100,000 miles.
        People tend to forget that small effects multiplied by millions (of vehicles) are significant.
        I read that when GM was pushing the DRL idea in the 90’s they also successfully petitioned the government to disconnect the DRL during the CAFE testing.

        Hey Sajeev, concerning your comment ‘Daytime running lights *do* significantly reduce your risk of being in a crash during the daytime”, I would really love to see your sources backing up that statement.

        There was a definite logic back in the day of having uniform sealed beam headlights. That regulation was intended to prevent exactly what we have today, wildly variant and in many cases visually debilitating headlight performance.

    • 0 avatar

      I should add that back in the days of carburetors and manually adjusted idle speeds there were some cars that the condition for setting idle speed included having the headlights (and cooling fan) on. The particular cars that come to mind are the earliest Honda Civics. When the fan and headlights were shut off after setting the idle you could see the rpm bump up thanks to the reduced load.

  • avatar

    Personally I would take a Xenon HID kit over an LED kit anyday. Xenons have a nice long throw that illuminates the road better than any LED projection bulb that I have seen. And they are warm enough in the winter to keep the light housing clean and clear. They are expensive, but worth every penny.

  • avatar

    The problem with most after market HID kits is that they are not self-leveling and can be seriously anti-social for other motorists.

    The is a good reason why all OEM HID headlights are required to have self leveling functionality.

  • avatar

    My girlfriend had a 2012 Volvo C70 with stock high beams that looked like the second coming…amazing. Not sure if they were Xenon.

  • avatar

    Last night I was driving my 2007 335i, and admiring once again the good job that the stock BMW headlights do. Good beam patterns, high and low, headlights that turn with the wheels, smart cornering lamps. Height correcting, too, though with a coupe that rarely sees more than 2 people, that’s not a much needed feature.

    Why aren’t all cars this good?

    These lights are even better than the Bentley.

  • avatar

    Running a LED at reduced voltage and current will not cause it to burn up. If it is low enough it might not actually produce light but that won’t damage it.

  • avatar

    “Daytime running lights *do* significantly reduce your risk of being in a crash during the daytime”


    The other option, though, is to do what I did before DRLS, and *keep your headlights on all the time the car is running*.

    This is free, at the cost of remembering to turn them on.

    (I dunno the JK, but if it’s like many modern cars that kill the headlights automatically with power off, you can just leave the switch on “on”, possibly.)

    • 0 avatar

      Turning your full headlights on also turns on your taillights, which reduces the contrast when you put your brakes on. i.e. it can be harder for drivers behind you to tell when you’ve applied the brakes.

      IMO this creates a larger safety issue than it solves, and I would not drive with full headlights on during the day for this reason.

      It’s also not “free”. The alternator has to work to provide that electricity. Headlight bulbs burn out sooner.

      • 0 avatar

        Conversely, DRLs do NOT turn on the tail lights which I think is a bigger safety issue again. I see many cars after dusk whose owners have enough light from their DRLs to believe that their headlights are on. From the rear, these cars are almost invisible.

        • 0 avatar

          IMHO the whole DRL thing is far more symbolism and fashion rather than any actual safety. Their (deliberate) glare does mask other features nearby in the visual field, rendering them less visible.

  • avatar

    Oh boy. This is a major pet peeve for me. There are many cars running around in Southern Ontario with lights that dazzle the oncoming driver’s eyes. I think that there are more than one cause of this. First, many new cars are equipped with LED headlights from the factory. There appears to be a greater amount of non-beam spread with these. Second, they are not aligned correctly. The hefty fee that you pay to the dealer for pre-delivery inspection is supposed to cover adjusting the headlights. Does it get done? Nope. Is it done at the factory? Not really. Is headlight aim checked at an annual inspection or maintenance, No. Is it enforced by Police? No. Next, aftermarket conversions, Daniel Stern’s pet peeve. I don’t think this is a common. If well done, I have no objection. But they often aren’t. Next, intentional mis-adjustment. I saw a car recently that had excellent lights with a sharp horizontal cutoff, but they were aligned well above horizontal as I could see on the back of a large truck trailer. The line started almost at the top of the doors and descended as he approached. There must have been at least 2-3 degrees of elevation. In Europe this will get you a ticket.

    Regarding auto adjust beam level for HID lights, this is only mandatory in the EU. Not required elsewhere. Euro cars have them, but NA and Japanese, no.

    Regarding keeping full headlights on at all time, I have done this now for 60 years. The issue of being rear ended is a non issue. If it does, it is their problem, not yours. It is easier to see the back of the car in many lighting conditions such as dusk or driving into the low sun with the tail lights on. Besides, the best setup is to have the brake, tail, and turn indicator lights with separate bulbs. For the record the intensity ratio is very large – 5W to 20W, a 4:1 ratio. Then there is the Amber/Red discussion on which I have just as much to say. My Saabs don’t give me a choice. Ignition on = headlights on. It works.

    Finally on my cars with plastic headlight lenses there is a huge difference in performance between freshly polished and weathered lenses. The roughened surface scatters the light to the point that the beam almost disappears. The headlight washers seem to contribute to this roughness.

  • avatar

    Color me confused:

    “the king daddy of them all is the 8700 Evolution-J (here, or here) from JW Speaker: these units are plug-and-play in the JK (’07+) Wranglers.”

    OK, so JW Speaker makes a plug-and-play Evo light.

    “None of the LED headlamps linked here is an advisable choice if you do a lot of wintertime driving”

    Got it. You want to melt the snow and slush off the headlight.

    “and there’s now a heated-lens version of the JW Speaker lamp”

    Ah, so the JW Speaker lamp—which is plug-and-play specifically made for the JK Wrangler—comes in a heated-lens version. Great. Oh, but:

    “No heated-lens version of the JK-specific Evo-J lamps”

    Wait a minute. Either “there’s now a heated lens version of the JW Speaker lamp” OR “No heated-lens version of the (JW Speaker brand) JK-specific Evo-J lamp”. Either/or. Can’t be both.

    Which is it?

    Let me throw this in:

    “and you’ll need those anti-flicker/adapter pigtails.”

    For what? Not for the JW Speaker Evo-J lights; “these units are plug-and-play in the JK (’07+) Wranglers.”

    Journalism is a wonderful thing to learn.

    • 0 avatar

      Looks to me like the situation is this:

      JW Speaker makes 7″ round headlights that fit in anything that uses the standard 7″ round headlight format. They are available with or without a lens heater, they have standard H4/sealed beam style connectors, and they don’t have onboard anti-flicker.

      JW Speaker also makes 7″ round headlights specifically for the JK Wrangler. They’re physically the same, but they have a 9008-style connector to mate with the 9008-style socket on the JK Wrangler. Also they have onboard anti-flicker. But they don’t come in a hot-lens version.

      So if you want a hot-lens JW Speaker headlight on your JK Wrangler, you buy the universal model and a pair of socket converter adaptors with anti-flicker boxes built in.

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