Stop light bulbs

[Tom F OHIO]

Are the 32 cp stop light bulbs very bright compared to the standard bulb. I had the LED light set up in, but both had lights burned out. I see there are LED bulbs but you have to have an alternator. I do have one of Tom W.'s EVR in my 6 volt generator.

[RawhideKid]

Actually, there are 6v+ ground full LED tail lights for the stock system and the teacup tail lights, available that work quiet well providing you have good solid grounds. You shouldn't blow an LED with good grounds. Don't forget, the best "cutout" is the "electronic regulator", not the cutout for LEDs.

[Patrick L.]

I surprised the LEDs burnt out. Some have mentioned in the past having trouble with some LEDs though. There are LEDs that seem to work fine. Mine have been in for quite a few years now with no issues [ 6v +grd with Toms EVR]

I would think the bulbs that would need an alternator would be halogens.

Before changing to LEDs I had the 32 cp rear lights and was still rear-ended. Although I can't really contribute that to the rear lights. I believe it was just the woman not paying attention as she had plenty of room to drive around me.

And, to the original question, yes the 32 cp bulbs are somewhat brighter.

[29er]

... and I discovered painting the inside of the light housing white really helps.

[Big hammer]

Originally Posted by 29er

... and I discovered painting the inside of the light housing white really helps.

Times 2

[Benson]

Sponsored Links (Register now to hide all advertisements)

If they continue running into the back of your car ... try painting the trunk to look like the display screen of an iPhone!!!

[Tom F OHIO]

They do have the LED stop light bulbs available. Will they hurt a 6 volt generator or is it just not powerful enough to use? Also does painting the inside of the light make the light dispense better?

[SteveB31]

Halogen bulbs use a lot of power, hence the need for an alternator. LED bulbs use almost no electricity, do not require an alternator and last for years.

[Big hammer]

Originally Posted by Tom F OHIO

They do have the LED stop light bulbs available. Will they hurt a 6 volt generator or is it just not powerful enough to use? Also does painting the inside of the light make the light dispense better?

I don't think paint the inside white will help LED lights, they are to close to the lens. Incandescent bulbs with the white paint inside the house sure makes a big difference ! At least what I saw with my eyes !

[iverson]

if the LED stop light bulbs are brighter on the stock 6volt pos.ground does anyone know what part no.? or where to buy? to fit the 28 stop light? it cant help much but every little bit of safty helps

[RawhideKid]

Well, a friend of mine got the 6v+ ground LED lights, they fit really well, and are way way brighter than the incandescent bulbs, but those fit the teacup taillight.

Since my car came 12v and 2 rear drum taillights, I took the same style of LEDs and just reshaped the outer edges until they fit in the drum lights, works great for me. So, I don't see why the 6v- wouldn't work with just the changing of the outer dimension.

You may need to get a bit creative with the mounting inside the drum, but it should work well.

[mhsprecher]

I have LEDs I bought from an Australian guy at Hershey about 5 years ago. Still working great. I bought some extra bright incandescent bulbs from Sacramento Vintage Ford for my V8 truck and they work well, too. I painted the inside of the tail light white on my Toyota Landcruiser decades ago and that worked great, too.

[MikeK]

OK, the latent geek in me made me do it, so here goes-

To get back to the OP’s leading question, “Are the 32cp stop light bulbs very bright compared to the standard bulb?” I’ll throw some numbers out there for the bamboo slip-stick crowd.

Per SAE std. J573d Mar.1918, rev. Dec.1968, plus addition of later lumen ratings*:
Each lamp @6.4V (wet cell Pb voltage, nom ‘6V’ battery @ 12.65s.g., 68F)
21cp draws 2.63 amperes, produces 264 lumens
32cp draws 4.01 amperes, produces 402 lumens
* NOTE: Actual total luminosity is rated in circular candle power. The bulb markings are erroneously given as “cp” (candlepower) which is entirely a different unit of light. DON’T ASK!!!!

@7.1V (correct generator/factory mech. regulator set point), roughly 2800K color temp & 95 CRI
plus wattage comps & Halogen equiv watts for equal lumen outputs:
21cp draws 19 watts, 2.68 amperes, produces 308 lumens. Equiv. to 17W Halogen
32cp draws 29 watts, 4.08 amperes, produces 470 lumens. Equiv. to 26W Halogen

Halogens- 6V nom @ 7.2V, roughly 3000K color temp & 98 CRI
(These are the available capsules potted in bayonet sockets for tail & stop**)
10W = 185 lumens, draws 1.39 amperes
20W = 371 lumens, draws 2.78 amperes
**NOTE: A halogen capsule must reach 482+Fahrenheit to initiate the ‘Halogen cycle’. This takes about 45 seconds. It then takes at least one additional minute to remove the cold deposited Tungsten. If you do not keep your brake light on for that amount of continuous time or use them intermittently, as signal blinkers, your $$$ halogens will blacken and burn out faster than $100 becomes $2 in a casino. Halogens are designed to operate continuously with envelope temperatures of 650 – 1200 Fahrenheit.

LED’s. Are they brighter, and if so, brighter than what wattage or lumen output Tungsten or Halogen?:

A red LED produces approximately ZERO lumens (OK, now MikeK has really lost his marbles!)
There is no direct mathematical comparison. Welcome to voodoo land, here goes:

Lumens are a complex full spectrum output comparison weighted at different, inclusive wide points for human eye sensitivity. Red LED’s (unlike ‘white’ LED’s) produce a single specific wavelength. Doing the math for a single specific wavelength gives you near ZERO.

A tungsten lamp behind a red lens yields approximately 22% of the ‘white light’ lumens. There is a narrow band of mixed red light wavelengths, again confounding lumen calculation. The rest is absorbed, or filtered out by the lens.

You just can’t compare the two using either lumens or watts. Apples vs. Oranges. The only real way to compare ‘brightness’ would be to model the human eye response, either with live volunteers and an encephalograph, or use one of the available research maps of the complex interaction of human color spectral response (cones) at varying wavelengths influenced by B&W rod response and total brain stimulation and then apply it to a photometric map of each tail lamp’s output. Do I get my marbles back? (DO NOT reply)

Seat of the pants approach:
Stock model A taillights are dim.
Stock model A taillights with higher output bulbs are visible.
Stock model A taillights with higher output bulbs and the insides painted gloss white are very visible.
LED’s in the taillamp are bright directly on axis, very visible 30 degrees off axis, dim 60 degrees off axis. (Axial intensity is a whole ‘nother can-o-worms.)

$$$ approach:
Stock taillights suck, but you’re not out a penny. (Model A guys are not big spenders)
Painting them gloss white inside ($7 for a spray can) near doubles the output.
Adding higher cp bulbs costs $10 for all four bulbs.
Paint & higher cp bulbs gives very good light but cost $17
Halogens will cost a lot more and give you ??? (compare using date given above) and last how long?
LED’s will cost you $70 to $135 for a pair and burn the eyes out of the guy directly behind you, but traffic way to the side at an intersection won’t see much more than stock taillights.

Logic approach:
Many Model A’s (yours, not mine, ha ha!) produce nasty voltage spikes that will burn out standard, Halogen, and LED lamps. The LED’s are sensitive to short (20 millisecond) over voltages, Halogens and standard tungsten bulbs can handle much longer and higher spikes. Welcome to Vegas! Where are you going to put your money down, and how much? (I think I lost my marbles again)

[iverson]

MikeK thanks-- I think!

[Tom F OHIO]

Mike K. Will you get these spikes with an EVR installed. I didn't have one yet when my expensive pair of LED taillights half burned out on both sides. Don't know if I want to chance buying them again. Thanks Tom......

[MikeK]

Originally Posted by Tom F OHIO

Mike K. Will you get these spikes with an EVR installed. . . Thanks Tom......

Tom, Although a voltage regulator will keep a lid on spikes it does NOT address or correct the intermittent/ poor electrical ground path connections that caused them in the first place.

A voltage regulator's primary job is to limit the upper voltage output level. If you use it as a Band-Aid to mask the spike problem, then other problems will eventually ensue. Many guys with original gennys and good wiring, including all ground/earth paths, NEVER have spikes that damage their $$$ LED's.

I would suggest you try the white paint and brighter bulbs approach first, as you progressively work your way through everything electrical, including earth/ground paths. You may be pleasantly surprised and find the paint & bright bulbs approach yields taillights that are more visible than the LED's.

[Mike V. Florida]

To put several things into one post,

No, you do not need an alternator for LED bulbs

Yes, you need the correct polarity LEDs for your car, Neg ground for neg ground LEDs and Pos ground for pos ground LEDs. The wrong type for your and they will blow out.

Swapping to neg ground on an otherwise stock 6-volt system, generator, pos ground is as easy as swapping the wires on the battery, coil, ammeter, and flashing the generator.

[30ccpickup]

Originally Posted by Benson

If they continue running into the back of your car ... try painting the trunk to look like the display screen of an iPhone!!!

Good idea, but I tried that and they just followed me home.

[Bruce Adams]

I did not see LEDs included in the OP's original question, but my 6 Volt LEDS and Third Brake Light make as much light as I could want. Here is a photo as I make a left turn. I have 6 volts with an alternator. I have chosen to go ALL RED since I figure its easier than teaching the world about amber brake lamps, particularly when my Third Brake Light is Red.

[CarlG]

My lights look pretty much like Bruce shows above, except that mine are 12v.