Up­grad­ing light­ing

The lat­est ad­vances in head­lamp tech­nol­ogy and a guide to fit­ting LED day­time run­ning lights.

Car Mechanics (UK) - - Contents -

Light and dark are fun­da­men­tal to hu­man psy­chol­ogy and phys­i­ol­ogy. In na­ture, we have evolved to func­tion dur­ing day­light and pro­duce the hor­mone, mela­tonin, to pro­mote sleep at night. Pro­duc­ing ar­ti­fi­cial light has also been es­sen­tial to our sur­vival, ce­ment­ing a link be­tween light and safety.

Yet, where an­cient civil­i­sa­tions would strug­gle to keep a fire lit (the lat­est rash of re­al­ity tele­vi­sion pro­grammes high­light how crit­i­cal a fire is for sur­vival), modern man takes light­ing for granted, be­cause it is avail­able at the flick of a switch.

Scared of the dark?

In an au­to­mo­tive con­text, the as­so­ci­a­tion be­tween light and safety is pro­moted heav­ily but not al­ways cor­rectly. At OEM level, safety is the rea­son why day­time run­ning lights (DRLS) have be­come manda­tory on new cars, even though some peo­ple view them as un­nec­es­sary – and even dan­ger­ous – in coun­tries out­side of Scan­di­navia. In­deed, the ‘brighter is bet­ter’ hymn is sung by many light bulb re­tail­ers, im­ply­ing that their prod­ucts are su­pe­rior and safer. This may lead you to buy the bright­est bulbs pos­si­ble, while for­get­ting, or ig­nor­ing, the equally es­sen­tial safety is­sue re­lated to daz­zling on­com­ing mo­torists.

Ring Au­to­mo­tive, the Uk-based ve­hi­cle light­ing and af­ter­mar­ket

spe­cial­ist and our tech­ni­cal part­ner for this fea­ture, ac­knowl­edges that, while its range of high per­for­mance head­lamp bulbs in­crease bright­ness, the en­gi­neer­ing both of the bulb and the head­lamp op­tics make the ex­tra light work­able and safe.

This is one rea­son why the MOT test started en­forc­ing leg­is­la­tion, ban­ning HID head­lamp con­ver­sion kits ear­lier this year. Bright­ness should not be the only tech­ni­cal con­sid­er­a­tion when buy­ing any bulb, let alone an up­rated one.

Evo­lu­tion of bulbs

Us­ing elec­tric­ity for light­ing was sug­gested by the sci­en­tist Humphrey Davy in the early 1800s, af­ter he no­ticed that elec­tric­ity arced through the air and pro­duced light when he shorted out ter­mi­nals. Arc lights had evolved by the mid-19th cen­tury, but they were in­ef­fi­cient and the elec­trodes de­manded a com­plex clock­work mech­a­nism to main­tain an ad­e­quate gap, be­cause the in­tense heat eroded them away. As gas would pro­vide a more pop­u­lar means of do­mes­tic light­ing, some of the ear­li­est cars used ei­ther can­dles or gas head­lights, both of which were fairly in­ef­fec­tive. Elec­tric light­ing was not tech­ni­cally vi­able un­til the in­tro­duc­tion of more ef­fi­cient dy­namos and the fil­a­ment bulb.

Davy had also no­ticed that a me­tal wire heated-up when elec­tric­ity passed through it. Un­for­tu­nately, this was of lit­tle use, be­cause it would re­act with am­bi­ent oxy­gen and melt. En­clos­ing the wire within a glass tube, evac­u­at­ing the air and pres­suris­ing the void with in­ert gases (such as ni­tro­gen and ar­gon) of­fered a so­lu­tion. Ex­per­i­ments with dif­fer­ent fil­a­ment ma­te­ri­als fol­lowed, cul­mi­nat­ing with tung­sten, be­cause it pos­sesses the high­est melt­ing point of all pure met­als. Within the glass, the tung­sten is coiled and the tighter the coil is wound, the more heat is gen­er­ated and the brighter it glows.

Tung­sten-halo­gen bulbs ap­peared in the 1950s, with minute quan­ti­ties of io­dine, or bromine gases, added at an even higher pres­sure within the glass en­ve­lope, which in­creased the life­span of the fil­a­ment by en­cour­ag­ing any evap­o­rated part of the coil to re­de­posit it­self. As 12-volt electrics be­came uni­ver­sal, th­ese bulbs pro­duced dou­ble the light and lasted twice as long. De­vel­oped by Lu­cas, the H4 twin-fil­a­ment tung­sten-halo­gen bulb con­tained one fil­a­ment each for dipped and main beam lights and be­came vir­tu­ally uni­ver­sal in ve­hi­cles, al­though sin­gle fil­a­ment bulbs (H7) have since re­gained pop­u­lar­ity, as they tend to of­fer su­pe­rior per­for­mance.

More re­cently, dual per­for­mance lamps (such as H15) com­bine main beam and day­time run­ning light fil­a­ments. Some re­cent cars fea­ture cor­ner­ing lights, usu­ally lo­cated in the fog­light aper­tures be­neath the head­lights, which are ac­ti­vated by the steer­ing an­gle sen­sor, al­though this can con­fuse other mo­torists into think­ing that the turn­ing car in front of them has a bro­ken foglamp. Some cars are pro­grammed to cut-out the DRLS, should there be a con­flict be­tween in­di­cat­ing a change of di­rec­tion and mark­ing out the car.

The ar­rival of HID

Some changes have had a more pos­i­tive ef­fect. De­spite re­fine­ments made to their de­sign and con­struc­tion, tung­sten­halo­gen bulbs re­main rel­a­tively in­ef­fi­cient, be­cause they waste be­tween 70-90% of the con­sumed en­ergy as heat. Look­ing to im­prove head­lamp ef­fi­ciency, ve­hi­cle aes­thet­ics and op­tics, lamp de­sign­ers turned to High In­ten­sity Dis­charge (HID) bulbs to re­place the tra­di­tional fil­a­ment-type. This also ne­ces­si­tated a com­plete re­design of the head­light’s in­ter­nals.

Th­ese HID bulbs – called ‘burn­ers’ – bor­row cer­tain el­e­ments from en­er­gysav­ing tube lights, them­selves based on tech­nol­ogy from the waste­ful arc light. Known also as ‘strip lights’, the elec­trodes are placed at ei­ther end of a glass tube and, af­ter the air is evac­u­ated, the tube fills with a glow­ing high­volt­age arc. Once the in­side of the tube is coated with a flu­o­res­cent pow­der, the dan­ger­ous ul­tra­vi­o­let glow is con­verted to brighter, safer and us­able light. HID burn­ers do not utilise flu­o­res­cence, but rely in­stead on a num­ber of dif­fer­ent gases and salts within the burner. Like fil­a­ment bulbs, HIDS pro­duce ul­tra­vi­o­let light that can dam­age the head­light, al­though ad­vanced glass tech­nol­ogy fil­ters it out. HIDS are some­times called ‘xenons’, but the nomen­cla­ture can be con­fus­ing, be­cause cer­tain halo­gen bulbs can also con­tain xenon gas.

As HID bulbs do not have tiny fil­a­ments at ei­ther end of a glass tube to ‘start them up’, they re­quire an ig­niter to cre­ate the, ap­prox­i­mately, 2000 volts nec­es­sary to va­por­ise the salts. An elec­tri­cal bal­last – a re­sis­tor that lim­its the cur­rent – then takes over to main­tain the run­ning power at be­tween 35-85 volts, at which point the to­tal power con­sump­tion tends to be much lower than that of an equiv­a­lent fil­a­ment bulb, while the light out­put is dou­ble. The ig­niter is in­cluded on D1, D3 and D5 HID bulbs, but the bal­last is al­ways a sep­a­rate com­po­nent. The dif­fer­ent light out­put char­ac­ter­is­tics of the HID burner means that the op­tics of a fil­a­ment head­light are in­com­pat­i­ble, due to the in­crease in scat­ter that af­fects the beam pat­tern and height­ens sig­nif­i­cantly the risk of daz­zling on­com­ing mo­torists. This is a prime rea­son why HID (and, for that mat­ter, LED) con­ver­sion head­light bulbs are il­le­gal to sell, fit and use on the road.

Early D1 and D2 HID burn­ers con­tain mer­cury vapour, which is not cap­tured when the car is scrapped. To re­spond to leg­is­la­tion ban­ning the heavy me­tal, car man­u­fac­tur­ers in­tro­duced D3 and D4 mer­cury-free HID bulbs in 2012, al­though re­place­ment mer­cury-con­tain­ing parts are avail­able. How­ever, the old and new bulbs are not in­ter­change­able. Some new types of ex­tra-ef­fi­cient 25-watt HID bulbs have been in­tro­duced (such as D5S, D6S and D8S) but they are fairly un­com­mon.

Old HIDS should be dis­posed as haz­ardous waste and not sim­ply placed in house­hold rub­bish.

LED lamps

As there is no road-le­gal Light Emit­ting Diode re­place­ment bulb, cer­tain newer cars with LED light­ing have sealed lamp units. The en­closed na­ture of their con­struc­tion en­sures that the LED mod­ule and the op­tics of the lamp work to­gether ac­cu­rately. Car­mak­ers pre­fer LED head­lights both for aes­thetic rea­sons, with LED lamps mar­keted strongly as a premium ex­tra, and for their low en­ergy con­sump­tion and the as­so­ci­ated re­duc­tions in CO2 emis­sions. Yet, even LEDS do not break the tra­di­tional link be­tween light and heat, and some LED head­lights con­tain ei­ther con­sid­er­able heat sinks and/or cool­ing fans.

While LED head­lamps are fit­ted to some of the newer ve­hi­cles on the used car mar­ket, do not as­sume that they of­fer su­pe­rior per­for­mance over HID, or even fil­a­ment bulbs. From a DIY per­spec­tive, con­sider also that, should an LED mod­ule fail, the com­plete head­light will need to be re­placed and that af­ter­mar­ket al­ter­na­tives are un­avail­able. In the near fu­ture, spe­cial­ist LED head­light re­pair is likely to be of­fered by var­i­ous af­ter­mar­ket ECU re­pair busi­nesses.

LED Ma­trix light­ing is be­com­ing pop­u­lar, where in­di­vid­ual LED mod­ules are con­trolled via a wind­screen­mounted cam­era to pro­vide auto-dip, or speed adap­tion func­tions, with the lat­est ver­sions map­ping on­com­ing mo­torists and switch­ing-off ar­eas of light to sur­round but not daz­zle them. Vaux­hall’s In­tellilux is one such sys­tem, while Audi and Volvo have de­vel­oped their adap­tive head­lights to pro­vide in­di­vid­ual il­lu­mi­na­tion for pedes­tri­ans and an­i­mals.

Ac­cord­ing to Michael Ko­herr, Ford of Europe’s light­ing re­search en­gi­neer, light­ing is go­ing to be­come even more so­phis­ti­cated: “We are now de­vel­op­ing new spot-light­ing tech­nol­ogy that helps draw the driver’s at­ten­tion to pedes­tri­ans, cy­clists and even large an­i­mals in the ve­hi­cle’s path. This would use an in­frared cam­era to lo­cate and track peo­ple and big­ger an­i­mals up to 120 me­tres away.”

What goes wrong?

Back in the realms of cur­rent tech­nol­ogy, fil­a­ments can sim­ply snap, but you can de­tect im­pend­ing break­age by iden­ti­fy­ing the black­ened re­mains of evap­o­rated tung­sten on the in­side of the bulb’s glass. Un­like HID burn­ers, how­ever, fil­a­ment bulb per­for­mance does not drop with time. While your HID bulb may last for more than a decade, its per­for­mance de­te­ri­o­rates as the mol­e­cules of gases and salts within the burner not only age but also dif­fuse grad­u­ally through the glass. The re­sult is a de­te­ri­o­ra­tion in light out­put and, be­cause the process is grad­ual (with sodium va­cat­ing af­ter the first few months, mak­ing the light glow whiter, be­fore dim­ming grad­u­ally) the owner of an older car tends not to no­tice, be­cause the head­light still works, al­beit at a re­duced ca­pac­ity. Ring rec­om­mends that HID burn­ers are re­placed in pairs ev­ery five years.

The main op­er­at­ing con­di­tion that re­duces HID life is re­peated switch­ing on and off. The con­trol gear can fail as well. Should the bal­last break, the start-up ig­niter will not work. If the ig­niter fails, you may hear a ‘click­ing’ sound from the af­fected head­light. In any case, a flash­ing dipped beam dash­board tell-tale may be one way of in­di­cat­ing that a fault code has been logged. Most Hid-equipped cars are fit­ted with self-lev­el­ling and head­lamp wash­ers. As

cer­tain Ja­panese mod­els were fail­ing UK MOT tests, such as Mit­subishi Lancer Evo­lu­tion XIIIS, which had fac­tory HIDS but no wash­ers, the MOT reg­u­la­tions stip­u­late that, if lev­ellers/wash­ers are fit­ted as stan­dard, they must work.

While adap­tive LED and LED Ma­trix head­lights re­quire pe­ri­odic ad­just­ment and cal­i­bra­tion via di­ag­nos­tics (gen­eral ad­vice on dig­i­tal cal­i­bra­tion was out­lined in the Oc­to­ber 2018 is­sue of CM), the head­light will need to be re­placed as a com­plete unit, which will ne­ces­si­tate pro­gram­ming, align­ment and cal­i­bra­tion. The head­lights them­selves can suf­fer from var­i­ous ail­ments. Other than stonechip dam­age, or an im­pact that breaks the mounts, the in­ter­nal re­flec­tive ma­te­rial can de­tach. While sev­eral spe­cial­ists of­fer a re­sil­ver­ing ser­vice, this tends to be less suc­cess­ful if the coat­ing is ap­plied to a plas­tic base. A more com­mon phe­nom­e­non on newer head­lights, where a glass lens has been re­placed by a plas­tic cover, is the sur­face be­com­ing opaque. While long-term UV light ex­po­sure from the sun tends to be the cul­prit, in­ex­pen­sive bulbs can lack ul­tra­vi­o­let block­ers, which has­tens de­te­ri­o­ra­tion.

Buy­ing bulbs

Low-qual­ity com­po­nents are a grow­ing prob­lem and bulbs are one of the most pop­u­lar tar­gets for coun­ter­feit­ers. You need to be able to place trust in your sup­plier and its brand.

Ring’s ve­hi­cle light­ing di­vi­sion has been es­tab­lished for more than 40 years and its test and R&D fa­cil­i­ties are lo­cated at its West York­shire base. “Cus­tomers can trust our bulb range,” says Matthew Fla­herty, prod­uct man­ager at Ring. “We do not sim­ply print our logo on other peo­ple’s bulbs; we part­ner only with lead­ing man­u­fac­tur­ers to pro­duce bulbs that have the high­est qual­ity, and li­aise closely with our sup­pli­ers around both Europe and Asia, many of which we have worked with closely for over 20 years.”

With re­search re­veal­ing that one in four af­ter­mar­ket bulbs are built to a poor stan­dard, buy­ing du­bi­ous items from un­known sources is likely to re­strict your vi­sion and in­crease light scat­ter, or ‘glare’.

As pro­duc­tion ac­cu­racy is so crit­i­cal to road safety, au­to­mo­tive bulbs are one of the few af­ter­mar­ket parts that must be cer­ti­fied for their per­for­mance. This means they should be Type Ap­proved and bear the ap­pro­pri­ate ‘E’ mark. The leg­is­la­tion caps var­i­ous de­sign and per­for­mance char­ac­ter­is­tics, such as fil­a­ment align­ment, power con­sump­tion, bright­ness, colour tem­per­a­ture and base de­sign, mak­ing it an of­fence to use a non-type Ap­proved bulb in an on-road ex­te­rior lamp, be­cause of the safety im­pli­ca­tions. You can use non-ap­proved bulbs (in­clud­ing LED con­ver­sions) within the in­te­rior, as long as the light out­put is not di­rected out­side. While you can buy stan­dard non-type Ap­proved lamps, not only are they il­le­gal to use on the open road but they could also be a false econ­omy. The car might fail its MOT on dipped beam align­ment and the po­ten­tial lack of UV light block­ers may dam­age the head­light. Al­ter­na­tively, lower gas pres­sures may be used to com­pen­sate for the cheaper glass at the ex­pense of dura­bil­ity.

Up­grad­ing op­tions

When up­grad­ing fil­a­ment bulbs, much de­pends on your needs. As some cars ne­ces­si­tate dis­man­tling of the fron­tend just to change a head­light bulb, fit­ting long-life re­place­ments may be prefer­able. The longer life is at­trib­uted to them run­ning cooler, with the trade­off be­ing a slight re­duc­tion in out­put.

As Ring’s Matthew Fla­herty says: “Type Ap­proval de­mands that an H7 bulb, for ex­am­ple, runs at 1500 lu­mens, with a tol­er­ance of 10% – so a long-life bulb will run within the lower side of that 10%. A per­for­mance road-le­gal bulb can be up to 10% brighter, while re­main­ing within the Type Ap­proval lim­its. The fil­a­ment is wound tighter, too, which en­sures a smaller fo­cal point, which places more light on the road where it is needed by the driver.”

While Matthew Fla­herty ad­mits that us­ing ob­vi­ously blue lights at the front of your car is il­le­gal in the UK, he ex­plains why the blue coat­ings on Ring’s roadle­gal up­graded bulbs will not fall foul of the au­thor­i­ties: “When a fil­a­ment glows brighter, you change its colour tem­per­a­ture. Coat­ing tech­nol­ogy, ap­plied to the glass, al­ters it again, so you can keep the bulb le­gal but use a white, or bluer light, to re­place yel­low, which of­fers bet­ter re­flec­tion from road fur­ni­ture, such as sig­nage, with­out stray­ing from the Type Ap­proval colour and bright­ness lim­its. Again, if you are un­sure, check that the bulbs are E-marked so they can be used on the road.”

Cost is an an­other fac­tor. While high-per­for­mance bulbs are mar­keted as premium prod­ucts, ex­tra and more ex­pen­sive gases may also be in­cluded, such as xenon. Il­le­gal up­dates While fit­ting up­rated E-marked bulbs of the same light type is ac­cept­able, mix­ing and match­ing dif­fer­ent tech­nolo­gies is not. For ex­am­ple, plac­ing HID, or LED, bulbs in halo­gen lamps is tech­ni­cally im­pos­si­ble, be­cause they have dif­fer­ent bases to pre­vent ac­ci­den­tal fit­ting. This has led to the de­lib­er­ate cre­ation of ‘Franken­stein bulbs’, which have halo­gen bases but HID/LED tops, so they can be fit­ted into lamps de­signed for fil­a­ment bulbs. Due to their hy­brid con­struc­tion, it is im­pos­si­ble to meet the re­quired safety stan­dards, mean­ing that they are il­le­gal to sell, fit and use on Bri­tish roads. Due to the lack of any for­mal cer­ti­fi­ca­tion, the qual­ity of such bulbs can be ques­tion­able. Many of them are avail­able through on­line mar­ket­places, where some un­scrupu­lous sell­ers claim they are le­gal to use.

You may find such items, es­pe­cially LED side­light con­ver­sion bulbs, of­fered for sale at rep­utable re­tail­ers, but state­ments about their non-le­gal­ity for on-road use can be hid­den away in the small print on the pack­ag­ing, so look care­fully. If you drive an older car, you might have read that you can up­date its light­ing with con­ver­sion bulbs, be­cause Type Ap­proval reg­u­la­tions do not ap­ply to var­i­ous lamps be­yond a cer­tain age. Un­for­tu­nately, the re­search is in­cor­rect, be­cause the as­sump­tion is based on orig­i­nal parts of the Bri­tish Road Ve­hi­cle Light­ing Reg­u­la­tions from 1989, not the later reg­u­la­tions that su­per­seded them.

The re­place­ment head­light bulbs mar­ket, in par­tic­u­lar, of­fers great scope for im­prove­ments. But buy care­fully – make the wrong choice and you could make your car un­safe and il­le­gal.

Head­lights have evolved con­sid­er­ably. Pic­tured are per­for­mance com­par­isons of a 1908 Ford Model T’s gas head­lamps against a Ford An­glia 105e’s fil­a­ment dipped beam and the HID Xenon of a 2016 Ford Mus­tang.

Fil­a­ment bulb pro­duc­tion is a pre­cise art. Misalign­ment re­sults in poor out­put and glare, which is why you must in­sist on Type Ap­proved bulbs, which are a le­gal re­quire­ment for on-road use.

Pic­tured are D1 and D3 HID burn­ers with an in­te­gral ig­niter. Note the dif­fer­ent mould­ing used for the plas­tic con­nec­tor, be­cause D3 burn­ers (on the left) con­tain no mer­cury and have a dif­fer­ent elec­tri­cal bal­last spec­i­fi­ca­tion.

Ring has con­ducted re­search into the ef­fects of age­ing HID burn­ers. Pic­tured above is the light out­put from a new D3 bulb com­pared to the one be­low that is 10 years old. The loss in out­put is quite dra­matic, even though the old bulb would still pass the MOT.

HID elec­tri­cal bal­lasts tend to be fixed to the bot­tom of the head­light mould­ing and re­place­ment should be straight­for­ward. If the ig­niter is not in­te­grated with the HID burner, a sheathed ca­ble trans­mits 10,000 volts from the bal­last to the burner. Al­ways fol­low the safety in­struc­tions, sup­plied with the new bulb.

Both bulbs and com­plete lamp units (in­clud­ing sealed LED lamps) should carry E-marks in or­der to be road-le­gal.

LED Ma­trix front lamps work in con­junc­tion with a cam­era. This Audi unit can de­tect and il­lu­mi­nate a safe walk­way for pedes­tri­ans.

Here's why LED con­ver­sion bulbs are a poor up­grade. The im­age on the right shows the ex­te­rior lamp’s op­tics work­ing with the orig­i­nal fil­a­ment bulb to cre­ate an even, bright halo. The LED’S lightemit­ting char­ac­ter­is­tics, shown at left, re­sult in a less ef­fi­cient lamp.

Pic­tured is the re­sult of fit­ting a roadle­gal up­graded side­light bulb, com­pared with a stan­dard item. The one on the right, made by Ring (Xenon3500k 501), has a blue coat­ing, which acts to re­move the yel­low/or­ange light to pro­duce an out­put that still com­plies with Type Ap­proval.

Sealed LED cen­tral brake lamps have been used for many years. They will fail the MOT if fewer than half of the mod­ules are work­ing. You may be able to break open the seal to re­pair them – in this case, wa­ter had en­tered the unit, cor­rod­ing the re­sis­tors.

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