Mr. Dare? (LED 1157 bulbs)

[yellow98cobra]

would these work as direct replacement tail light bulbs. with out any modifactions?

http://www.ebay.com/itm/WHITE-LED-1157-12-VOLT-TAIL-LIGHT-BRAKE-STOP-TURN-SIGNAL-LAMP-BULBS-PAIR-120SMD-/231002239643?pt=Motors_Car_Truck_Parts_Accessories&fits=Year%3A1960%7CModel%3AThunderbird&hash=item35c8ce729b&vxp=mtr

[simplyconnected]

I have to answer your question by asking one...
Do these bulbs draw 2.1 amps? <--this is just the stop light side.
If the answer is, 'yes', then they will work as a direct replacement IF they fit. An 1157 bulb is 2" high. These are 2-1/4" high.

If the answer is, 'no', then buy them for your trailer.

I quickly looked at the listing and didn't see a rating for these LEDs. I suggest you call California and ask.

Your Squarebird flasher unit works by current draw. Mechanical flasher units usually come in 'two-bulb' (front turn signal, rear signal, and dash bulb) units OR 'three-bulb' (front turn signal, two rear signals on each side, and a dash bulb) units.

When 'extra' bulbs were added to the circuit (like when you plug in a trailer), the turn signals would speed up and more current would sometimes damage the turn signal switch in the column.

LEDs came to the rescue for trailer guys because they draw very little current, don't heat up, last forever and come in different colors. The turn signals in your car would hardly know the trailer is there.

Without a trailer, if you simply change your car bulbs to low current LEDs, your flasher unit would slow to a snail's pace or simply not flash at all. To remedy this, electronic flasher units use a time-base instead of current.

I have heard of LED bulbs with a large resistor to simulate a 1157 bulb. The resistor dumps current to ground but keeps the flasher at the correct rate.

120SMD are the type of LEDs. 120 is the candle power of each LED. SMD = surface mounted device. 120s are very bright.

I hope this helps. - Dave

[yellow98cobra]

Ok Thanks for that advice. I was just surfing ebay ads for 1960 T Birds and saw these and was curious.
Thanks again, Eric

[DKheld]

Been some discussion on this for the MGA's I restore. Tiny little brake lights compared to the Tbird and they are down low.

Can't find the article I'm looking for at the moment that compared bulbs (with pics) but here is a tech article from our "guru". Note that he recommends RED LED's.

http://mgaguru.com/mgtech/electric/et247a.htm

Also in this article (although a bit old) I guess the only thing available were bulbs that pointed downward so they wouldn't work. The ones you linked to only had a few LED's pointing out to the rear - the rest outward - you would have to rely on reflectivity for the rest of the illumination to the rear.

Maybe something like this in red if they drew enough current?

http://www.ebay.com/itm/2pcs-BAY15D-1157-24-LED-Car-Auto-Brake-Stop-Signal-White-Light-Bulb-Lamp-12V-US-/181339790268?pt=Motors_Car_Truck_Parts_Accessories&hash=item2a38b19bbc&vxp=mtr

Keep us posted on how they work if you decide to try the LED's.

Eric (the other Eric )

[simplyconnected]

...here is a tech article from our "guru". Note that he recommends RED LED's.
http://mgaguru.com/mgtech/electric/et247a.htm...

...LEDs came to the rescue for trailer guys because they draw very little current, don't heat up, last forever and come in different colors. The turn signals in your car would hardly know the trailer is there.
...I have heard of LED bulbs with a large resistor to simulate a 1157 bulb. The resistor dumps current to ground but keeps the flasher at the correct rate...

I realize our electronic technology has changed in the passed ten years. I got 'color' covered but your guru suggested using a resistor that is wayyyy undersized. If used with a Squarebird, that resistor would burn it out by simply sitting at a light with your foot on the brake.

He talks about a 1157 but shows a 1156 (with one end contact), then he links to a site that is unavailable.

If you are considering LEDs, this is a much better deal at $8/ea:
CLICK HERE
I don't often suggest sales on eBay but this one includes two bulbs with free shipping (from Murrieta, California).

The base is a 15D (like an 1157) and the diodes are 5050's. I buy these diodes individually on eBay. They are super bright and work beautifully under your hood or in the trunk. They are 3-volt LEDs, so I put five in a series and stretch them out over a wide area so they don't cast shadows. There are brighter LEDs (like the 5730) but they need a proper heat sink.

One important note for cars with positive ground: LEDs are polarity sensitive and do not work with positive ground (if you use ground). The bulbs you see on the market are internally wired for negative ground, for 99% of the cars. There are a few, like the German Amphicar and pre-1956 Ford cars that were originally wired w/positive ground. To get around this, some bulbs turn around in their base to reverse polarity. You have to search for this type.

There's nothing wrong with being creative. I love the crisp response time of LED tail lights. Put LED lights in all your tail sockets and wire them in parallel. If two resistors are necessary, the values are easy to figure out and they are inexpensive. - Dave

[JohnG]

So Dave, just to be clear - - the bulbs you provided the link to - - we can just replace the 1157s with them with no other modifications, and the blinker system will function like it did with the 1157s?

John

[simplyconnected]

John, it's always best to ask, 'exactly what is the current draw?'

Even if you get an answer, measure the current with one of those cheap $3 multi-meters from Harbor Freight. These ammeters will measure up to ten amps. We are looking for two amps.

Here's the deal:
A regular 1157 bulb draws 2.1 amps on the large filament (stop/turn). Let's assume you only have one rear signal/stop lamp on each side.

I'm going to pull numbers out of the air and say a LED lamp draws 1/10th the amps of an incandescent 1157 bulb. So, I hypothetically measure 0.21 amps with my ammeter.

The difference in current is (2.1a - .21a = 1.89 amps) To dump 1.89 amps let's use Ohm's Law to find the proper resistor: (Volts=Amps*Resistance or Volts/Amps=Res)
Volts = 12
Amps = 1.89
So, 12v/1.89a=6.3Ω (ohms).
(Understand, we are dumping this current so that this light acts the same as a standard 1157 bulb, which your flasher unit is made for. We are keeping the car OEM but using LED tail and stop light bulbs. This can easily be reversed at any time and is not a permanent change.)

Here's the trick... If you use more LED lights by filling all your lenses, the resistance goes up and the wattage goes down. But let's stick with one bulb for now. We need to figure one last part for our resistor; wattage. In order to keep our resistor cool, we commonly double the wattage rating (not the resistance).

So, Watts=Amps*Volts or 1.89a * 12v = 22.6 Watts. Let's double the watts to 45w. So we need a 6.3 ohm resistor at 45 Watts. We can safely round to a 6 ohm resistor at 50 watts.
A eBay search for, '6 ohm 50 watt resistors' produces them for $2.60-$3/each including shipping.

Now, let's play. Assume you have a '60 Squarebird and you fill all three sockets with LED lamps (to take the place of one 1157). Add the currents (.21*3=.63 Amps total, subtracted from the initial 2.1= 1.47 Amps we need to dump.

The new resistor (for 3 LEDs on each side) would be: 12v/1.47a = 8Ω (per side)
(You see, adding more lights uses more current so we can dump fewer amps with a larger resistor value.)
Watts for the new setup would be: Watts=1.47a*12v or 17.6w (doubled) = 35 Watts
A eBay search for,'8 ohm 50 watt resistors' produces them for $3/each including shipping.

Remember, I'm pulling these currents out of the air just to show how we figure resistance. The real advantage is, these LEDs don't burn out and neither do the resistors. The resistors may be mounted under the dash or in the trunk. One is required per side (LH/RH). The other advantage is the tail lights. Tail lights don't need a resistor, they simply use less current. (Personally, I would rewire the headlight switch so the front parking lights stay on with the headlights. The savings in rear LED tail lights offsets this added power demand on the system. For on-coming traffic, this marks the corners of the front in case a headlight burns out.) - Dave

[JohnG]

Dave

Thank you for your very detailed and illuminating comments . . . . LEDs certainly seem the future.

John

[simplyconnected]

Sometimes I get ahead of myself. You guys who aren't exactly 'thrilled' at the idea of messing with electricity, let me explain a few basics:

An incandescent light bulb (like the kind we've always used from the beginning) IS a resistor. In fact it is a big resistor. We use it for the bright light it makes. It also makes enough heat to burn you or melt plastic. We waste more power to make unwanted heat than we do for the benefit of making light. Up until recently we lived with heat by using large housings to dissipate heat and to protect the hot bulb from water splash.

Light Emitting Diode bulbs offer equal light without producing heat, at about 1/10th the power. Back in Squarebird days, there were no LEDs, so our signal systems are designed us use 1157 light bulbs.

If we replace a regular 1157 bulb with an LED bulb, exactly where does this resistor go? The resistor is connected to ground on one end (like the light bulb), and to the turn signal wire on the other end. We say, the resistor is connected across the light bulb. It's that easy.

Since we get to use flexible wires, this resistor (or resistors) may be mounted anywhere, like behind sheet metal in your trunk. Then the wires connect, one to ground and the other to the bulb wire (possibly at the bullet connector).

How big should the wire be? We are only passing two amps so very small wire can be used. #18AWG copper stranded wire will work just fine.

The RH turn signals need one resistor, and the LH signal needs one resistor. The size of that resistor is determined by how many LED bulbs you use.

No other changes to your car are needed, just LED lights and two resistors. - Dave

[yellow98cobra]

Dave thanks for clearing that up, as you had lost (scared) me at wire it under the dash... found this online
Resistor wiring details

If you have fitted LED bulbs in place of normal filament type indicator bulbs or stop/tail lights, you may experience fast flashing of the indicators or blown bulb warnings on the
dash. To cure these problems you will need to fit load resistors across each LED bulb as shown below.
The load resistor has to be connected to the two wires that go to the indicator or tail light bulb holder, one end to the postive (live) wire, the other to the negative (earth) wire.
This makes the indicator relay or bulb check circuit see a normal load in the circuit and operate correctly
Same ebay seller has resistors http://www.ebay.com/itm/Load-Resisto...item5403930adc
Please note that resistors can get hot during use, do not mount them on plastic. ( I am assuming I can splice into the black & the green wire shown in picture #2)

[yellow98cobra]

60 Tbird has 1 stop light, turn signal, tail light. 1 tail light, stop light and 1 back up light. So does only the turn signal need the resistor?

[simplyconnected]

Eric, I did say you can put the resistors under the dash. You only need one resistor for each side if all your rear turn signal bulbs are LEDs. (I don't know why anyone would mix LEDs with incandescent bulbs.) Determine how many stop/turn bulbs you want (on each side) and wire them together.

The way your brake/flasher system works is, your turn signals interrupt the brake lights. That means your turn signal wires come from the steering column (bullet connectors under the dash).

It also means you can make a 'Y' jumper w/male & female bullet connectors and one resistor lead in the middle, and simply plug them in at the steering column connections. The other resistor wire connects to ground.

If your 'resistor jumper' is more convenient to mount under the trunk lid, then do it there. Because this is a parallel circuit, the resistors may be mounted where ever you like.

Eric, your picture is for the wrong type bulb (with two connections, not three). It also has a separate ground wire. Ours use the metal housing for ground. Check out the picture below:

[yellow98cobra]

OK I like the sound of this... "It also means you can make a 'Y' jumper w/male & female bullet connectors and one resistor lead in the middle, and simply plug them in at the steering column connections. The other resistor wire connects to ground."
Just to be clear the 3 lights on each side are. Two outboard lights, Tail light/stop light 1157 bulbs with 2 wires and body ground (the outer most bulb is also the blinker), the back up light is an 1156 bulb single wire with body ground. All 3 come off of the same left and right turn signal wires?

Parts list if I have it right, would be.
4ea Tail light/stop lights 1157 bulbs (LED)
2ea 1156 bulb (LED)
2ea 6 ohm 50 watt resistors

[simplyconnected]

LED bulbs that are not on a flasher circuit need no resistors. They simply plug right in and are allowed to operate at a reduced current. These include, license plate bulbs, courtesy light bulbs, dash light bulbs, glove box bulb, backup light bulbs and tail light bulbs (not the turn or stop portion). If they ever offer LED headlights, they would not need a resistor either.

This next part pertains to each side of the car:
I went through the math to determine proper resistor size for the number of LED bulbs you want to add, when taking the place of ONE 1157. For instance, I take out one rear 1157 but now I want two rear turn signal LEDs to take its place. I understand Squarebirds may have only one turn signal in the rear. Remove the single-pin socket and add a 1157 socket (C0SZ 13410-A) for each additional second stop/turn/tail LED bulb.

Wire all the new additional LED bulbs to the original socket and use the resistor calculations for adding LEDs. If you want to get fancy, you may make them sequential later on.

Let me say it another way... If you remove a front 1157, you need a 6Ω resistor for the new LED bulb.

If you remove a rear 1157, you will need a 6Ω resistor for the new LED bulb.

IN ADDITION to removing one rear 1157 and ADDING more LED bulbs to the rear, here are different combinations (the choice is yours):

You could possibly want just one LED bulb for each side (just the one rear or one front turn signal) add a 6Ω resistor,

Two LEDs; one for the front and one rear turn signal on each side (remove two 1157s and add two 6Ω resistors),

Two rear turn signal LEDs: (remove one 1157 and add a two LED bulbs), add one 6Ω resistor,

If you don't want (or don't have) a backup light you can change them all to brake/turn LEDs.

Three LEDs, one front and two rear: (remove two 1157, add three LEDs and add two 6Ω resistors ),

Three LEDs, all in the rear: (remove one 1157 and add three LEDs and one 8Ω resistor)

Four LEDs, one front and three rear: (remove two 1157 bulbs, add four LEDs, add one 6Ω and one 8Ω resistor.

Let's put things in perspective. People add trailers and they simply parallel their car's lights. Because the current goes up, the flashers blink faster.

Adding one LED light to an already existing system changes the current by 1/10th of one more 1157 bulb. So, modern trailers can hook up with no changes.

We have an opposite situation where we are removing the 2.1 amps of one 1157 bulb and replacing it with an LED of 1/10th the current. If we add two, we're adding 1/5th. If we add three, we're adding .6amps. Now, .6 is **** close to 1/2, which is still 1/4 of the 1157 we pulled out.

The point I'm making is, the flasher unit will still go too slow. We add more resistance to run more amps through the flasher unit, but this current goes to ground. The less resistance we add, the more current flows. <--this is hard for some folks to grasp. Is there that much of a difference between 6Ω and 8Ω? It depends on the voltage we are working with. Since we only have 12 volts, two Ohms of resistance can dial-in what we are really after. Could we simply use all 6Ω or 8Ω resistors? Yes, but I'm trying to perfectly match an 1157 bulb's current draw, not for the sake of bulb brilliance (that remains the same), but for the rate of flasher.

On another note, I said the brakes are interrupted by the turn signals. There are two power feeds going up the steering column, one from the brake light switch and the other from the flasher unit. When you pull the signal lever, the brake light switch disconnects from one side of the car and the flasher unit power takes over. That's why your front signals flash but are separated from the brake lights. It all happens in the steering column and that switch is only good for so many amps. If you really need to add big trailer lights current, do it with relays that are fed from the battery, and switched by the stop/turn bulbs. - Dave

[simplyconnected]

Hey, how did this turn out? Did you ever buy LEDs?

would these work as direct replacement tail light bulbs. with out any modifactions?
http://www.ebay.com/itm/WHITE-LED-11...ce729b&vxp=mtr