Need LED bulb help

I am trying to find an LED bulb to replace an 1154 tail light bulb. I have found some companies that say they have one but they are calling it an 1157.

The problem with this is that the 1157 is a 12 volt bulb and the 1154 is 6 volts. I don't think that they are interchangable but I don't know much about LED's.

This is for the tail light on a 1940 Ford. I have found some complete replacement LED tail lights but they are all 12 volt. The car belongs to my BIL and he insists on keeping the 6 volt system.

Any help would be appreciated.

The LED might work with 6 or 12V. Or not. The problem I have with the 1157 LED replacements is that they suck in light output compared to an incandescent bulb. I have not found one that was worth plugging in. Unless there is a new one out in the past 2 years, I would stick with the conventional bulb.

I did purchase some 18 wheeler trailer LED lights to experiment with mounting inside the regular lens. We'll see.

Dr. Hess; The light output from the incandescent bulb sucks too. I've done enough research to find out that the problem is a poorly designed reflector in the original tail light. It send most of the light output up in the air rather than back.

GPW: Unfortunately I would need to go the other direction ie: step up from 6 to 12 volts

honestly, the step up in voltage from 6 to 12 will only hurt lights, starter, and wiper motor

and even the starter can be nursed along for years as long as you do not use it too much at any one time

He could also convert it to 8 Volts. The spec on my 47 Plymouth was "6 to 8 Volts." You just put an 8 Volt battery in, adjusted the regulator and that was it.

Hal wrote: Dr. Hess; The light output from the incandescent bulb sucks too. I've done enough research to find out that the problem is a poorly designed reflector in the original tail light. It send most of the light output up in the air rather than back. GPW: Unfortunately I would need to go the other direction ie: step up from 6 to 12 volts

Sorry... read that too quickly. You can go get a bag of cheap ultra-bright 5v LEDs and roll your own solution pretty easily. Knock the glass out of a standard bulb... use a little clear tub and tile caulk, a couple resistors and some solder. Use as many LEDs as you need to get the right light output.

Dr. Hess, m_m: Biggest part of the problem is that my BIL is a fanatic about keeping much of the car original. He has had an orignal generator that has been converted to a 12v alternator seting on the shelf in the garage for 3 years now and won't put it on.

GPS: Yep, I will probably have to dig out my old text books so I can do some calculations and "roll my own" bulbs.

8 volts is "original." LED tail lights are not original.

Dr. Hess wrote: 8 volts is "original." LED tail lights are not original.

Correct. But his idea of original is 6 volts. The LED lights are my idea so I won't have to stick around at every cruise-in we go to so he will have "tail lights" on the way home.

We import LED signs and other LED lights (industrial, not auto). I would be willing to bet that you won't find any super bright 6v LED replacement lights in an auto type base. The market doesn't make them a high-profile product choice and more than likely no one has asked for their production.

I think roll-your-own is definitely the right route. You can still get any of the parts you need at Radio Shack.

If you really want stupid bright, check out some of the SMD type LEDs that come as little chips. they cost a little more and are a little more finicky about voltage, but you are talking lumen output that approaches headlights. Just watch the heat dissipation.

Hal wrote: the problem is a poorly designed reflector in the original tail light. It send most of the light output up in the air rather than back.

This is true with a lot of cars of the past. In my '66 Mustang, I painted the reflector, which is basically the entire insides of the the tail light assembly, white, and it made a world of difference. Good grounds help, too.

Also doesn't help that cars from that era have really small tail lights mounted really low to the ground. Would he concede to a well hidden third brake light, like up in the rear window?

The 40 Ford is pretty popular. There are several aftermarket LED taillight assemblies out there that bolt in the stock location. From the outside they look stock and bolt into the stock location. They use a panel of LEDs so the whole lens is filled, not just a pinpoint like the drop in bulbs.

A street rod supplier called Watson's Street Works makes a "6-to-12" converter for their 3rd brake light kit. Might be worth a call to them to see if it could be used for the standard taillights. Probably would need more than one though. They don't carry the LED '40 taillight assemblies.

I don't work for them, but I have used some of their other products and have been very happy with the quality.

ultraclyde wrote: We import LED signs and other LED lights (industrial, not auto). I would be willing to bet that you won't find any super bright 6v LED replacement lights in an auto type base. The market doesn't make them a high-profile product choice and more than likely no one has asked for their production. If you really want stupid bright, check out some of the SMD type LEDs

Right, there don't seem to be any 6v auto bulbs available. Funny part is that up thru 1939 you can buy complete tail lights that have been converted to LED. But they don't make them for a 1940. Guess its because in 1940 they added those new fangled things called turnsignals.

SMD's would be nice but that would require a fancy circuit board which I'm not sure I could make. Since the tail lights are tilted back at a 45* angle I'm not sure I can even get standard LEDs mounted so they will point in the right direction. I'll have to go to RS and see what they have.

Rob_Mopar wrote: The 40 Ford is pretty popular. There are several aftermarket LED taillight assemblies out there that bolt in the stock location. From the outside they look stock and bolt into the stock location. They use a panel of LEDs so the whole lens is filled, not just a pinpoint like the drop in bulbs.

LInks Please. I haven't found any yet. Have found them for up to 1939 but not for 1940.

Edit: I have found some but they were all 12 volt and as noted above I need 6 volt

The Technostalgia ones need 12V. But I think you can use the 6-12V converter from Watson's to run them.

Technostalgia '40 lights

Watson's 6v to 12v converter (Quick edit, scroll down toward the bottom of the page)

The Watson's kit is for a 3rd brake light kit, so you might need two for the regular taillights. But you would need to call and confirm with them if it would work or not. I haven't tried it, all my stuff is 12V.

Rob: Thanks, that looks like an easier way to go than trying to make my own.

Glad to help.

If you get it done, a hotlink of the '40 Ford getting the lights will be required.

Rob_Mopar wrote: Glad to help. If you get it done, a hotlink of the '40 Ford getting the lights will be required.

I can do the pics right now

weird.. he is running an offy, has polished bits in the engine compartment.. but won't convert to 12v.. especially since it is a mod NOBODY will see? (except for him if he drives at night)

It says Offenhouser on the rocker cover. That's just about as cool as it gets!

So how did he end up wiring the LEDs in?

Hal wrote: I've done enough research to find out that the problem is a poorly designed reflector in the original tail light. It send most of the light output up in the air rather than back.

OK, so why not fix that problem instead?

Things don't move much in a taillight assembly, so roll your own with a little aluminum foil.

mad_machine wrote: weird.. he is running an offy, has polished bits in the engine compartment.. but won't convert to 12v.. especially since it is a mod NOBODY will see? (except for him if he drives at night)

He has fixed it up just like one he had in high school. And wants to keep it that way. I never said he made any sense.