Headlight Double Fillement Bulb

[Humblej]

I never liked the headlight bulbs I have been using for decades, 6V, 32-32 cp. Original bulbs in my 1924 have a low beam that is more like a parking light than a headlight. I would like to drive with my lights on during the day like modern running lights, but the insufficient output of the generator places a drain of about 10 amps on the battery. I found some vintage Tung-Sol, no1172, 6V headlight bulbs with 32-6 cp on e-bay. My ammeter is not very accurate so am not sure exactly the power consumption, but the small ammeter on my 26-27 switch is neg 2 amps with the light switch to LOW, neg 10 or so amps with light switch to ON position. I suspect the original bulbs may have been 24-2, but 32-6 will work fine for me.

[Jahn_Wright]

There are lots of opinions on LED bulbs, many by people who haven't tried them. For headlights, I use #87455 purchased from LEDLight.com located in Arizona. Very low amperage draw. https://www.ledlight.com/6-volt-negativ ... spx?Page=4

[John.Zibell]

These seem to work well. The Ford headlight reflector isn't needed to focus the beam, it is all internal to the bulb. https://www.logolites.com/products/led- ... eadlights/

[TRDxB2]

Logo Lights look like a good alternative to both filament & other styles of LED light bulb.
The Model T headlight socket is either BA15S (single beam) or BA15D (hi/Low Beam). The issue with using non standard bulbs is the that source of the light needs to be basically a pin point to be adjusted into the focal point of the reflector. Its important to understand that the reflected light is then projected onto the fluted lens that projects a light beam out onto the road (or wherever). The PROs & CONs of switching to LED bulbs are less amperage draw and apparent brighter light. However their designs don't emit their light into the focal point of the reflector. Actually this is not much different than an original bulb not being adjusted properly. This diagram illustrates the result. So if you would look at the headlight directly an unfocused bulb would make the headlight lens look brighter than properly focused one. Its also important to know that the color of the light (warm 3500, daylight 6000) will make things look brighter (actually whiter) when in fact the same amount of light, measured in lumens, is reflect onto the surface.
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The specifications for the Logo Lights indicate that both the Low & High beam light sources are relatively at the some point allowing for the lens to focus the light properly. As I indicated early the fluted lens is design to focus the light, so I'm uncertain if this will interfere with the Logo Light beam.
While the objective is to illuminate the road at night (note I didn't say brighter headlights) the decision to change light source, falls back on amperage draw. In looking at the specifications for the Logo Lights, the amperage draw is outstanding for Low & High beam. Since it a focused beam, the condition of ones reflectors is of less concern. In fact a bit hazy one may disguise the presence of the led.
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I would prefer these at 4000K over the Logo Lights 6500K for a more period look ($35 vs $49) shipping for 1 bulb

[Humblej]

The video of the logolites seem to have the right focus, so should work. My intrest is regarding conventional headlight bulbs, and what bulbs were the factory bulbs. I could not find anything in the Ford Service Bulletins and Ford Service Manual regarding the specific bulbs. I did find something in a 1928 Western Auto Supply catalog, they list headlight bulbs for Ford cars with starters as 21-2 cp or 32-6 cp bulbs. Cars without starters are magneto bulbs so that is a different story. The generic part number for the 32-6 cp bulbs is 1172. These show up on Ebay under Eveready, Edison, Mazda, Tung-Sol, etc. The bulbs have "TOP" marked on the barrel for correct orientation. I have not found the generic number for 21-2 cp. I did find some 21-2 6-8 V bulbs that are of new manufacturer that are probably for tail lights, they do have "TOP" marked on the barrel but they do not have the typical headlight bulb shape so they may or may not focus, will have to try it and see.

[Dennis_Brown]

Are the headlight bulbs from LED Light in Arizona a focused bulb or do they rely on polished reflectors?

[TRDxB2]

Are the headlight bulbs from LED Light in Arizona a focused bulb or do they rely on polished reflectors?

I didn't see any in their on-line catalogue indicating a Focused Beam. A lens is needed for that. They did have one bulb, wouldn't fit a Model T, that had a lens but the description said "here is only one filament. Built with 24 quantity side firing high quality 3030 chips. 6 3030 led chips for forward firing plus a lens. " A forward firing chips and a lens. So no idea of the light beam is a spot light, flood light etc.

[DHort]

$50 each. I will pass

[Luke]

$50 each. I will pass

Dave,

The LEDs I use were circa $3 or thereabouts direct from the manufacturer, they focus well and have lasted. That said the LEDs often advised by others appear to have a good track record and I guess you would have local support - perhaps worth the price?

Otherwise, if you'd like to be able to make an informed decision, or would simply like a little more detail on headlamps, this thread may be of interest: https://www.mtfca.com/phpBB3/viewtopic.php?f=2&t=25440

Luke.

[babychadwick]

Going through the wiring on this Buick I have a puzzling situation regarding the headlights which are the same as a double contact T. The LED bulbs don't work unless I put an incandescent in one socket. 2 LED nothing, either socket either LED nothing until I put a plain bulb in then the single LED lights. 12v to the socket and the ground is fine. Most puzzling!

[TRDxB2]

$50 each. I will pass

The decision on on LED bulb cost depends on ones objective.
-Most LED bulbs are low amperage & brighter than filament bubs, but you must check the specification. I'd avoid ones that don't provide amperage & lumen value. The color rating should be between 4000K - 6500K. If you don't like those cars with bright whit light coming at you at night those are at the high end 6000K.
-If you want to be seen in the daytime, most of the less expensive ones will suffice as daytime running lights and allow other drivers to see you at night
-Night time driving depends on what the headlights can illuminate on the sides of the road.

IMHO The less expensive ones that people are satisfied with are a good choice for using during the day as daytime running lights and driving down rural roads at night. Driving in the suburbs might need the $50 ons

[Luke]

Going through the wiring on this Buick I have a puzzling situation regarding the headlights which are the same as a double contact T. The LED bulbs don't work unless I put an incandescent in one socket. 2 LED nothing, either socket either LED nothing until I put a plain bulb in then the single LED lights. 12v to the socket and the ground is fine. Most puzzling!

Chad,

LEDs are a very low current device compared to an incandescent. If there was something wrong with your wiring and you effectively put a LED lamp in series with an incandescent the LED would light, but the incandescent wouldn't. Some LED's are also polarity sensitive, something I would check before going much further with determining any issue because the issue could be as simple as this. It could also be that you haven't got the correct LED lamp (see this thread where Matt discovered he'd ordered the wrong type: https://www.mtfca.com/phpBB3/viewtopic.php?f=2&t=34485 )

The thread I referenced has a number of steps you could follow, but to summarise: having first checked the LED polarity and type issue, I would very closely inspect your wiring and grounds to see that the wiring is correctly switched and is commonly polarised, and that the grounds - particularly at the socket end - are also well connected. By commonly polarised I mean that the wiring between the two headlamp sockets connects to the same 'filament' in each lamp for example.

Then I'd check the sockets themselves, sometimes they can be fault, and I would concentrate initially just on one headlamp. Running a separate ground wire directly from the socket back to the battery would be a start (ie. just a handy test wire, not a permanent wire), then likewise with each filament connection. At some point there should be a 'light bulb' moment when you 'bypass' the fault and things start working. That should localise the actual issue and you should be able to fix it from there.

Luke.

[Original Smith]

I'm using the original 21-2 cp bulbs in my car. They don't do much in the city, but are fine when it's dark and there are no street lights.

[Humblej]

Larry,
What is the amp draw for 21cp?

[TRDxB2]

Larry,
What is the amp draw for 21cp?

Likely it depends on the bulb brand
The following was an entry error on my part that Luke pointed out (Calculation Watts to Amps Watts / volts = Amps , 21/6 = 3.5 amps per filament)
I meant to use the watts for the example 21 CP bulb specification attached
Calculation Watts to Amps Watts / volts = Amps , 16.83/6.4 = 2.63 amps per filament
Also if you look at the specification the watt value changes with the voltage drops
There is an approximation of CP to Watts for filament bulbs that is dependent on a performance factor P (assume 100) & standardized variable 12.57
CP = W * P/12.57 or CP*12.57/100 21*12.57/100 = 2.64 https://calculator.academy/watts-to-can ... alculator/
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As Larry indicated these work fine when it's dark and there are no street lights. They should bright enough to alert on-coming drivers
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Some seem to be more concerned about the affect of amp draw on the battery & recharging than light output. So lets say your ammeter is at minus 6 amps (for whatever load you have on it - coils, lights, USB charger) and you have a 100Ah fully charged battery. 100Ah / 6amps = 16 hours but that's not reality & would drain the battery. So one can easily expect 10 hours of use. Recharging time depends on the amperage output of the charging system, rated battery Ah, current Ah and even temperature. The formula for estimating assuming needing a full charge. Ah of the Battery / output amps of the charger.
100Ah battery on a 6v smart battery tender output of 2 amps = 100Ah/2amps = 50 hrs on a 6v 5amp charger 100Ah/5amps = 20 hrs
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Battery charging - ignore the EV reference - https://ev-lectron.com/blogs/blog/how-m ... battery-at

[Luke]

Frank,

Candlepower (CP) isn't the same as Watts, Ohms law isn't applicable to calculate current draw directly from CP. It may be that Larry's bulbs draw 3.5A, but not necessarily.

Also, with regard to a typical Pb battery, if you want to get maximum life out of them you shouldn't discharge beyond about 30% of their nominal capacity. Thus a 100Ah cell really has circa 30Ah available to the user before they would begin to shorten their life by drawing down further.

Specific cell construction and chemistry can enhance this, and other cell types such as LiFePO4 may be discharged down by as much as 90% without concern, in which case you're able to safely utilise much more of that battery capacity at the standard rate. As LiFePO4 is becoming more prevalent, is a comparatively 'safe' chemistry, and is close to Pb in terms of cell voltage and charging regime, they can be a great alternative if you need extended runtime.

Finally there's Peukert's law which, keeping it simple, essentially means that the available runtime will also be affected by the rate at which current is being drawn from a cell. Cells are usually rated at a standard discharge rate (say 20hr); if you draw more than this the cell will tend to have a shorter runtime than stated, if you draw less it will have a longer runtime. In the case of Pb this could make as much as say 25% difference, with LiFePO4 it could be as little as 1%.

Thus in the example you give it is likely that drawing just 2A from a standard 100Ah Pb battery would in fact give you more than 50hrs runtime (if you chose to discharge the battery to destruction, and ignored the voltage drop), conversely if you drew say 50A you'd have less than 2hrs to run.

Luke.

[TRDxB2]

Frank,
Candlepower (CP) isn't the same as Watts, Ohms law isn't applicable to calculate current draw directly from CP. It may be that Larry's bulbs draw 3.5A, but not necessarily.
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Luke.

Oops, did I do that? Yes I know CP isn't Watts my mistake I thought I corrected that and added some specs I found for a 21 CP bulb
Might have forgot to hit submit on the initial correction
I am correcting my original entry & include the specification

Thanks for the noticing!

[babychadwick]

Chad,
...series with an incandescent the LED would light, but the incandescent wouldn't.

Some LED's are also polarity sensitive, something I would check before going much further....

It could also be that you haven't got the correct LED lamp ..

... I would very closely inspect your wiring and grounds to see that the wiring is correctly switched...

... two headlamp sockets connects to the same 'filament' in each lamp....

...Then I'd check the sockets themselves, sometimes they can be fault...

...Running a separate ground wire directly from the socket back to the battery...

....At some point there should be a 'light bulb' moment when you 'bypass' the fault and things start working....

An incandescent will light but led won't

Checked polarity first as I am aware of the need for polarity to be correct

Led lamp fits correct socket and voltage.

I have just finished repairing/replacing all the wiring in the car as well as tearing apart and cleaning the switches

Sockets truoughout the car have been rebuilt

Tried checking the ground, no fault there.

Yes, I had gone through your suggestions and DID have a lightbulb moment which is why it is puzzling and thought I would share. I found someone else that has experienced the same problem. LEDs won't work unless there is an incandescent or resistor in the circuit. On my Lincoln this wasn't an issue as the taillights used incandescent and we're wired thru the same switch. On the Buick the switch has a separate circuit for the tail and gauges allowing for headlights to be "bright" "dim" or "parking"!

[Original Smith]

I don't know much about electricity, but can follow a wiring diagram. I also know the bulbs they used to make are not the same as what's available now.
The 21 cp bulb pictured above is not the same appearance as the originals. It also doesn't mention what the lower cp is.
I don't think they even use the cp designation any more?

[babychadwick]

Perhaps it is the flow of electricity rather than the potential difference? This doesn't really make sense to me but trying the bulbs directly to a battery there is nothing. DC doesn't pulse like AC so perhaps there isn't enough resistance in the LED to complete the circuit. As a result an incandescent completes the circuit and then the LED wired in parallel lights?

[Luke]

I don't think they even use the cp designation any more?

Larry,

That's quite correct, the UK candlepower became candelas (a SI unit) in the 1940's I think. There is an approximate conversion between the two with one candlepower being about 98% of a candela, and they originated as a measure of the intensity of a light source compared to a 'standard candle'.

Today manufacturers tend to use lumens (lm), which is a different thing again, effectively being a measure of (visible) light over a unit of time. Lumens are relatable to CP via something like: 1 lm = (0.98 x 1CP) x sr where sr is a square radian. The reason for this is to consider a light source that radiates equally in all directions and, practically, what this means is that a 1CP light source would equate to about 12.3 lm.

Given an automotive bulb doesn't radiate equally in all directions, along with various other things, it's possible that 1CP could be very roughly equivalent to say 6-9lm. Thus your 21CP bulb might be ~120-190lm, but I need to stress this is very much a 2-minute back of the cigarette packet calc, and that someone may have actually measured this much more accurately (ie. I could be wildly wrong!).

Finally, as LEDs are measured in lumens, and consume much less current than an incandescent bulb, you could (again very roughly) say that for an equivalent light output a LED lamp might consume somewhere between 1/5th to 1/10th of the energy required to power an incandescent bulb.

Luke.

[Luke]

Perhaps it is the flow of electricity rather than the potential difference? This doesn't really make sense to me but trying the bulbs directly to a battery there is nothing. DC doesn't pulse like AC so perhaps there isn't enough resistance in the LED to complete the circuit. As a result an incandescent completes the circuit and then the LED wired in parallel lights?

Chad,

I confess to being slightly confused here. I thought that your earlier post indicated you'd found a problem, but perhaps not?

If you still have an issue, I would start by temporarily connecting a ground wire to the outer ring of the lamp socket directly back to the battery ground post (-ve for a -ve earth car), then take another wire from the other battery post and touch that to one or other of the socket 'centre' pins. The lamp should light at this point, if not then there's a polarity problem (if the LEDs are polarity conscious) or a socket problem.

If it does light up then the problem is further back and we could start a process to determine why.

Perhaps you could try this and report back?

Luke.

[babychadwick]

Luke-
Touching a ground from negative battery post to outside of lamp and a second from the positive to the terminal at the back and no light, that eliminates the car completely. Voltage is present and correct in the socket and as expected no light as it is more complicated but still the same circuit as the battery.

The puzzle is that if an incandescent is used somewhere in the circuit (no they aren't in series) then the LEDs work perfectly.

[Luke]

Luke-
Touching a ground from negative battery post to outside of lamp and a second from the positive to the terminal at the back and no light, that eliminates the car completely. Voltage is present and correct in the socket and as expected no light as it is more complicated but still the same circuit as the battery.

Chad,

Just so I'm clear - you've actually run two wires directly from the battery to the h/lamp socket and you get nothing from the led?

Luke.

[babychadwick]

Absolutely correct, I did that before the first post which is why I found it so puzzling. Trying that and finding no light I assumed the bulbs were bad. You can imagine my bewilderment when I put an incandescent and then they would light.

[Humblej]

How did an incandescent two filament bulb post become a LED wiring question post?

[babychadwick]

How did an incandescent two filament bulb post become a LED wiring question post?

Original post was regarding power draw and alternative options to what options might be available. My initial suggestion may have been looking into the generator and power produced but as it was regarding bulb power consumption vs. light output it has in my opinion remained "on topic"

[Luke]

Chad,

If you have directly run two wires from -ve and +ve of the battery to the h/lamp socket and the LED doesn't light then there can only be two possible causes:

(1) The LED is polarity-sensitive and the supply voltage is incorrectly polarised
(2) There is an issue with the h/lamp socket (most likely earthing)

A third option is some sort of hybrid of (1)+(2), btw that you can fit an incandescent which makes the LEDs work is not inconsistent with these things. I imagine you can sort it from there, would be interested to know the result.

Jeff,

I was surprised that your original post became something about LEDs almost immediately, however one hopes that the resultant discussion you started has been useful to some!

Luke.

[babychadwick]

Chad,

If you have directly run two wires from -ve and +ve of the battery to the h/lamp socket and the LED doesn't light then there can only be two possible causes:

(1) The LED is polarity-sensitive and the supply voltage is incorrectly polarised
(2) There is an issue with the h/lamp socket (most likely earthing)

A third option is some sort of hybrid of (1)+(2), btw that you can fit an incandescent which makes the LEDs work is not inconsistent with these things. I imagine you can sort it from there, would be interested to know the result.

As mentioned before I tried running directly from the battery to the bulb eliminating the possibility of a problem with socket. Knowing the polarity was correct but to double check thinking possibly the bulb had reversed polarity I reversed the wires and nothing. At that point I assumed naturally the bulbs were bad and had replacements sent. You can imagine my bewilderment when I went to put incandescent bulbs back in and the LED I was about to pull out lit up! I took it out and checked it on the battery -nothing. I tried the other LED, lights in the socket. Put both LED in -nothing! Swap out either with an incandescent and light as soon as the incandescent makes contact. This is why I first posted puzzling behavior.

[Luke]

Chad,

It can be difficult to fault-find these things at a distance, and we may have reached an impass, but I'm just checking you did read the thread I referenced earlier in which Matt describes a similar problem and eventual solution? https://www.mtfca.com/phpBB3/viewtopic.php?f=2&t=34485

Luke.

[babychadwick]

Puzzle solved apparently I need a ba15d automotive bulb and the seller listed as an ba15d auto/rv stop turn bulb and silly me since they never mentioned filiment or marine I assumed it was a stop/tail dual filiment ba15d base bulb. Now that I know since and I don't have time I'll simply rewire it for marine (single filiment dual base) and order something right. Then transfer the bulbs to the speedster as the ground has beed problematic in the past and it's just on/off light switch.

[jsaylor]

I see references to 24-2 and 32-6 incandescent bulbs. Those must be pretty dim on the low setting. I have always run 50-32 incandescent bulbs. The high amp draw is not really a concern since I rarely drive more than 30 miles after dark.

[TRDxB2]

Puzzle solved apparently I need a ba15d automotive bulb and the seller listed as an ba15d auto/rv stop turn bulb and silly me since they never mentioned filiment or marine I assumed it was a stop/tail dual filiment ba15d base bulb. Now that I know since and I don't have time I'll simply rewire it for marine (single filiment dual base) and order something right. Then transfer the bulbs to the speedster as the ground has beed problematic in the past and it's just on/off light switch.

Thought I'd add the difference between the connections & pins for automotive & marine. The marine bulbs could be used for those T's where the headlight bulbs are wired in series.
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The bulb base BA15 s/d are mostly called taillight bulbs Today. The BAY15 s/d are also taillight bulbs but brighter but have offset pins so they don't fit the T sockets.
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Snyder's sells the Focused LED bulb for a better price - not sure of color

[Humblej]

John,
Those 6cp and 2cp are dim, the same as a tail light, makes me think they are not intended as a low beam so much as a parking light or a light to be seen rather than a light to illuminate the road. Based on the wording in the Ford Service Bulletins, the focus and aim point for the headlights may be more for consideration to oncoming drivers rather than lighting up the road. The Ford aim point of 30" high at 25' ahead is not a good distance to drive very fast in the dark. Going to a brighter bulb will only make the same 25' aiming point brighter rather than illuminate a spot further down the road. If I was going to use a 50cp headlight I might be inclined to set up the aim point and focus for perhaps 35 or 40 feet instead of 25 feet. I do not know what modern headlight regulations are, but 100 years ago they must have been way more restrictive.

[Luke]

...I do not know what modern headlight regulations are, but 100 years ago they must have been way more restrictive.

Jeff,

If you'd like some early history this thread may provide: https://www.mtfca.com/phpBB3/viewtopic.php?f=2&t=25440

Chad,

Good that you've got it sorted now, hopefully Frank's diagram will assist in getting the right thing. FWIW I have in past filed off pins, and soldered new ones in place in order to utilise an otherwise perfect bulb that wouldn't fit...

Luke.

[jsaylor]

I had an experience with dim headlight bulbs. Was on an overnight tour from Bakersfield to Edwards AFB. The next afternoon, on the way home, I had my in-laws with me, it was getting dark about 50 miles from home. The car, a 27 Tudor Sedan, was a recent purchase and had not driven much at night. Those headlights were dim and more dim. Still had to drive over the Tehachapi Mountains. The next day I opened up the headlights and found the typical tail/brake combo with off set pins had been forced into the socket. I changed over to the 50-32 cp bulbs. I have used those ever since.