Exterior Lighting Resto/Maintenance/Upgrades

slantsixdan

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Here's how to make your exterior lights and signals (other than headlamps, that's another post) work better:

Lenses and reflectors
Clean the lenses Remove the lamp assembly from the car. Cars up to '76 or so, give or take depending on model, mostly have brake/tail and park/turn lamps on which the lenses can be removed from the reflectors. With a medium-soft nylon-bristle brush, scrub the inside and outside of each lens with hot water that's sudsy with liquid dish soap. Inspect the lenses for cracking, chalking, crazing and fading. If red lenses appear pinkish or orangish when you hold them up to a strong light, instead of decidedly red, they need to be replaced. Some lenses are more prone to deterioration than others; New lenses can be had for some old Mopars without too much difficulty or expense. If you need a cheap fix for faded lenses, go to a theatrical supply house and pick up a sheet of Roscolux #26. This is the material used in front of stage and movie-set lights. It's a transparent, flexible, thin plastic that's easily cut with scissors or a box knife -- use one of those tools to cut pieces of Roscolux to fit behind each faded lens.

Also clean the reflectors thoroughly, the same way (scrub with hot soapy water). Later-production cars have one-piece lens-and-reflector assemblies that can't be disassembled for cleaning and refurbishment. You can vigorously slosh hot soapy water in them and then rinse, and try to inspect the reflector. If it's dulled, your best move is to replace the assembly, though sometimes that's not possible or affordable. If you're clever you may figure out a way to disassemble it and then reassemble it satisfactorily.

Next, refurbish the reflecting surface of the reflectors. To do so, sand them as necessary, clean them with alcohol and then shoot them with "Chrome" or "Chrome Aluminum" spray paint from the hardware store. Do not use white paint, reflective tape, aluminum foil, mylar film, that high-cost paint that really does look exactly like chrome, or any other material. The plain ordinary hardware or parts store "Chrome" spray paint is virtually identical to the original material and so has the correct amount of diffusion; a mirror-shiny reflector is not what's wanted here.

Inspect the lens-to-reflector and housing-to-body gaskets. If they've deteriorated, new ones can be had from e.g. Gary Goers or DMT or other vendors.


Wiring and sockets
Inspect the sockets carefully. If the contacts have burned or corroded and/or the contact holder disc is rotten and/or the spring tension is no longer enough to hold the bulb securely, repair the socket. Socket repair pigtails (wire + spring + contacts + disc, easy to install) are available as follows (first number is NAPA Echlin, second number is Standard Motor Products):

LS 6451 or S60: Single contact w/rubber weatherseal
LS 6452 or S58: Double contact w/rubber weatherseal, holder disc index tab in line with contacts

LS 6226 or S23 : Single contact w/spring and backplate
LS 6228 or S24: Double contact w/spring and backplate, holder disc index tab in line with contacts
LS 6251 or S591: Double contact w/spring and backplate, holder disc index tab at 90° to contacts

Check the wiring, especially the grounds. It's very helpful to run a new main ground line from the engine compartment (battery negative, alternator housing, or attachment point of engine compartment ground strap) clear to the back of the car, where it can serve as the ground attachment point for all rear lights and other electrical stuff back there. You can pick up a lot of intensity and make the lamps come on much faster (shorter rise time for brake lights = more advance warning for following drivers) this way.
 
Part 2

Bulbs

Original equipment bulbs on most pre-'66 cars was as follows:

1034: dual-filament park/turn and brake tail. Clear bulb for use with red rear or amber front lens.

1034A or 1034NA: dual-filament park/turn. Amber bulb for use with clear front lens.

1141 or 1073: single-filament bulb. Reversing/backup lights (and single-function—brake-only, turn-only—lights not frequently found on old Mopars).

About 1965, the 1034 was replaced by the 1157 and the 1073/1141 by the 1156. These 1150-series bulbs put out the same amount of light, but draw slightly more current and last quite a bit longer. When changing from 1034s to 1157s, often it was (and is) necessary to replace the turn signal flasher, because the original would flash too fast if used with 1157s. Nowtimes, it's difficult to find a flasher calibrated for 1034s.

So, what to use for upgrade bulbs? Well first, here's what NOT to use: 2057s! People sometimes assume that because it's a higher number, it's a brighter bulb. No. The difference between 1157 and 2057 is in the "minor" (dim parking or tail) filament. On the 2057, the dim filament produces 2 candlepower. On the 1157, the dim filament produces 3 candlepower. The difference doesn't sound like much, but it's very large as a percentage. Both 1157 and 2057 produce 32 candlepower from the bright (brake or turn) filament.

If you're sticking with incandescent filament bulbs, the best (by far) bulb you can use in place of 1034 or 1157 is a Honda (car, not motorcycle) part number 34906-SL0-A01. It draws the same amount of current as 1157, but is much more efficient. It produces 43 candlepower on the bright (brake or turn) filament, and 3.5 candlepower on the dim (tail or parking) filament. It also has a nickel-plated base that is much more corrosion resistant than the plain brass base of an 1157, so it's a lot less likely to corrode and freeze/stick in the socket. The single-filament version (best replacement for 1156, 1141 and 1073 in all applications *except* reversing/backup lights) is Honda p/n 34903-SF1-A01. It produces 45 candlepower. These bulbs are very expensive relative to the ordinary type, but they have a lot of premium technology and materials/build in them. Lifespan is double to triple, the workmanship is extremely good, and it's cheap insurance against a traffic crash. It's worth buying these as genuine Honda parts (very well made by Stanley); the aftermarket items packaged by Sylvania, Wagner, GE, etc are all poor-quality trinkets from China that burn dim and die young.

For backup/reverse lights, the best incandescent bulb is a № 796. It is a 35W halogen bulb that produces 62 candlepower, or about double the light of an 1156 and about triple the light of an 1141. The wattage increase is small (35W vs. 28W); the wires and lenses will not notice or care) and the filament is in the right place. Neither of these compliments can be said of those 50W halogen backup bulbs you see in the parts stores! 50W is wayy too much current draw (100% overload!) for the stock wiring and switch, they produce way too much heat for safety near plastic lenses, and the filament's in the wrong place so the reflector doesn't work correctly with them. The 796s work great, and you finally get to see where you're going when backing at night.

Amber bulbs are a special case. The amber coating "steals" some of the light, so the output is lower. The bright filament inside an 1157A or 1157NA produces 32 candlepower, but what comes through the amber coating is 24 candlepower. Unfortunately, there's no amber equivalent of the Honda bulb for use in park/turn lights that have clear lenses. The next best thing is 2357NA, which draws about the same current as an 1157 and produces 30 candlepower despite the amber coating. 2357NA as well as their non-amber 2357 counterparts are less expensive than the Honda bulbs, but they don't have the anti-corrosion nickel-plated base or the Krypton gas fill, so they tend to blacken sooner than other bulbs if used in "bright" mode for prolonged periods (e.g. using a 2357 in brake lamp service). The 2357NA works fine in front park/turn service because turn signal service is short and intermittent, which limits bulb blackening and makes overall bulb life acceptable.

The '68-'71 sidemarker lamps can be made about 60% brighter with Osram № 3886X bulbs, which also fit directly in place of the 1895, 57, and 53 used in instrument cluster lights that take the metal bayonet-base bulbs. The '72-up sidemarker lights and '66-up instrument cluster lights take the all-glass wedge-base bulb. The Osram № 2886X is the one, about 75% brighter than a 194, 60% brighter than a 168. These are tough to find in North America; send me a PM if you're after them.
If your car has the little turn signal indicators mounted on top of the fenders, and one or both of them no longer flash, you can either spend $3.40 apiece at Year One for a replacement bulb with a plain brass base, or you can spend $10.60 and get a 10-pack of 'em with corrosionproof nickel-plated bases.
 
Part 3


LED retrofits

Until recently, the options were pathetic-joke "LED bulbs" or unsafe (but still costly) LED "panels" with or without custom taillights. Fortunately, the situation has changed for the better lately. There's still a mountain of unsafe garbage on the market, all of it marketed as an "upgrade", but now there are legitimate LED bulbs that actually work, with real optical engineering in them. Detailed info here. The ones to use in the brake/tail lights are these. For the backup/reverse lights (and amber-lens turn signals that take a single-filament bulb, not many old Mopars have these in North America) use these. There are these that work well in some front turn signals but not others; whether it's a yes or a no depends on what kind of optics your front turn signals use -- and that depends on the model and year. Generally if there's a bowl-shaped reflector behind/surrounding the bulb, it's a yes, but if there's just a box (housing) surrounding the bulb and the lens has circular optics spreading out from a central "bullseye", then it's no. (The red version of that bulb is here; same yes/no deal applies). Don't mess with "load resistors" (good way to louse up the reliability of the system), instead put in a flasher configured to work with LEDs.

By the way: whether or not they work OK is not a matter of peering at a light and going "Yep, looks nice and bright to me!". It's all objective and very detailed. There are specifications for minimum and maximum intensity, for each different function, through a large range of horizontal and vertical angles. That's to make sure that not only can the guy directly behind you see and recognise your brake lamps as brake lamps when he's sitting at about the same height as you, but so can the guy in the next lane over to the left, sitting down low in his Corvette...and so can the guy in the next lane over to the right, sitting way up high in his semi truck...and so can the guy on the on-ramp in his SUV. There are also specifications for the minimum intensity ratio, again through a large range of H and V angles, between functions that share a lit compartment (brake/tail, for instance, or park/turn). That's so that your taillamps can't be mistaken for brake lamps, or your brake lamps for taillamps. There are specifications for minimum projected active illuminated surface area, to make sure that the lamps, when lit, are "big" enough to do a reliable job of grabbing attention and quickly and accurately conveying the intended message. "Lights up red when I step on the brake" really is not good enough.

And there is an additional issue with LEDs that is only addressed effectively with the legitimate bulbs: Heat. Everyone knows LEDs produce hardly any heat, right? Wrong! LEDs are commonly considered to be low-heat devices due to the public's familiarity with small, low-output LEDs used for electronic control panels and other applications requiring only modest amounts of light. However, LEDs actually produce a significant amount of heat per unit of light output. Rather than being emitted together with the light as is the case with conventional light bulbs, an LED's heat is produced at the rear of the emitters. The difficulty is that LEDs' light output is extremely variable depending on temperature, with many types producing at 30° C (85° F) only 60% of the rated light output they produce at an emitter junction temperature 16° C (60° F). Take one hot day...add one traffic jam with extended brake light "on" time...and the LED-retrofit trinkets' output will drop to such a degree that the lamp assembly will no longer produce minimally adequate safety performance. Anybody can dream up a brand name and spend money to promote it—very few have the resources to actually make a product that works effectively and safely.

It's great that we finally have ones that work well. The advantages are big: much less current draw through our old/thin wires, instant light-up to give the driver behind more time to react, and you no longer have a hot filament near the lens, heating it up and melting a divot in it (more of a problem in some cars than others). But the magic's no good if the optics are wrong; stick to the legitimate items.
 
Part 4


Flashing front sidemarkers
Another cool and useful (and legal) upgrade is to make the front amber sidemarker lights on '70-up cars do double-duty as turn signal blinkers so pedestrians, cyclists and drivers in the next lane or cross street can see you signalling. If they aren't already wired this way, it's usually simple to make the change, see here. This can be done on '68 cars, but it's tougher because the early sidemarkers use only one wire and get their ground via body sheetmetal. This can be worked around, but it's more effort.

3rd central brake light
This is actually a really good safety device, though there was no shortage of grumbling when it was first introduced in 1986 in North America. It lets drivers behind you see you apply the brake earlier, and lets the drivers behind *them* see you do it, too. This is especially valuable for cars that have small/dim brake lights...'71-'73 Darts, among others. See the Allpar article. From the '80s through the mid '90s, the market was flooded with cruddy retrofit kits that were of very poor quality, looked ugly and had failure-prone logic modules that allowed easy (but failure prone) hookup to cars like ours, which have the brake lamp and turn signal function combined in one lamp. Most of us probably remember seeing an older American car with one of these junk retrofits...they never worked right. They'd blink with the left or right signals, or they'd be on when the brakes were off and off when the brakes were on, etc. Yuck. A good center brake light works well and doesn't really detract from the appearance of the car, but proper installation requires running one new wire from the brake lamp switch to the back of the car. This isn't very hard, all it involves is the wire itself, a piggyback terminal and removal of the left sill plates (which exposes the channel through which all the front-to-rear wiring runs).

If you install a central 3rd brake light, don't fall for the idea of putting a gadget on it that makes it blink/flash/strobe/"pulse". These are out there on the aftermarket, hyped as a "safety" upgrade (with zero basis in actual fact) and it seems like a common-sense kind of thing, but these gadgets do the opposite of what is claimed. The reason why car signal lights are standardized in their color, position, operation, etc. is so they transmit a clear, immediate message to other drivers. If you monkey with the operation of a car signal light, you force the driver behind you to figure out what your car's lights are trying to say. It might "only" take a fraction of a second, but at speed a fraction of a second's hesitation in applying the brakes can easily make the difference between a horn-honk and a crash. Just don't!

Daytime running lights
Opinions run high in the car enthusiast community. Some people are very enthusiastic haters of daytime running lights. Fact is, DRLs work: if your car has them, you're less likely to be in a crash. Moreover, just like with the 3rd brake light, you're significantly more likely to be hit if your old car doesn't have one. Most arguments against DRLs are legitimate, solid beefs about the problems caused by particular kinds of DRLs, not the concept itself.

Headlamp-based DRLs, both high and low beam, are very common in North America. They make a lot of problems: too much glare, too much fuel to run, they eat up expensive headlight bulbs, and they make the turn signals harder to see in daytime. And just turn on your headlamps during the day, either manually or automatically, isn't a good solution either. It increases fuel and bulb consumption, and because the taillamps are on it reduces the visual contrast between "not braking" and "Braking" conditions as your car is viewed from the rear.

Parking lamps are not DRLs; they're not anywhere near bright enough and the light isn't distributed through the right range of angles. And there's the brake/tail light issue, too.

For retrofit purposes, the best implementation is the full-time operation of the front directional signals (except, of course, when they are operating as signals). Chrysler has used this kind of DRL on some vehicles over the last twenty years, and you can enable it on any car with an easily-installed module -- see the Allpar article.

I guess that's enough rambling for now...if I've left anything out, I'm sure someone will ask about it.
 
why not white paint on the reflectors? some cars came factory with white paint.
 
Thanks Dan as always your knowledge base is by far the best when it come to automotive lighting. Thanks again!
 
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