LED tail lights

[Zeppelinium]

The early 70s Airstreams have a cast tail light assembly that was assembled with its light cans before it was installed. When you take the lens off the turn/stop light, you see the bulb end (back end) of two pop rivets. If you drill these out, it is still difficult to get the can out. This is due to the tight fight and the fact that these cans will probably be surrounded by a fair amount of corrosion. You can carefully extract them with a clamp, but be careful not to pull the inner flange ring (this ring has the three tabs for the lens screws) from the can. Once you get them out and sand off the corrosion, they go back in pretty easy.



This can has a central rubber device that holds the fiber optic sensor. In the can in the photo the fiber optics has come loose, but if it were intact the assembly can be unplugged from the can. If you install a disc-type LED, all the light is emitted from the outward facing surface, so the fiber optics will no longer work.



The backup light can (the outside can) comes out much easier.



Once you've modified your cans to contain the LEDs, resistors, and diodes, they can be connected back in using bullet connectors or solder. The tail light casting has an aluminum box behind it, between the casting and the inner skin, which makes moving the wire harness difficult and also makes it hard to snake new wire over to the marker light casting--I needed to do this because I added another backup light inside that casting. Making the wires accessible required a 5/8" hole in the middle of the casting and in the shell skin. Then a long piece of hanger provided the means for snaking the wire.



If you use a "bare" LED in the tail light circuit, you need a way to dim it when it's powered by the running light circuit. You also need to isolate the running light circuit from the turn/stop circuit. The hold bulb did this automatically because it was really two bulbs (two filaments inside the bulb). If you don't isolate the two circuits with a diode, the stop light circuit will ground out the running light, and vice versa the running light circuit will stop the turn blinker from operating. Why? I have no clue.



The photo of the installed lights clearly shows the additional backup light shining out the bottom of the marker light casting.



The next step is to install a switch that will allow the backup lights to be used as illumination around the parked Airstream. This requires two diodes to isolate the Airstream battery from the backup circuit in the tow vehicle (you wouldn't want to charge the battery through the backup circuit) and to prevent the Airstream from illuminating the tow vehicle backup lights, if you're still hooked up.

Zep

[Razinni]

Is anyone that you know of selling the LED equivalent of a two filament bulb that is plug and play?

[DKB_SATX]

There are a number of options for this, but some work better than others. Lots of them are highly directional, usually along the axis of the socket. That's not a good arrangement for '70s Airstream taillights.

Search (google, amazon, etc.) for LED 1157 bulb and you'll find a bunch of options.

There are some companies like led4rv.com that have some specialized replacements tailored to some of the Airstream taillights, they're not direct replacements for an 1157 bulb but they do plug into the socket.

EDIT: I should've scrolled up... Zeppelinium started this thread with some detailed photos about one type of specialized replacement.

[switz]

I needed to install (under the bed in the 25FB) a regular incandescent tail light bulb and socket for each rear LED brake light as the there was not enough power draw with the LED brake light bulbs to tell the Mercedes that the taillights were "attached" and thus the car thought the trailer was not connected.

Since the regular incandescent bulbs taillight stayed in the trailer when I switched to the Dodge truck, I do not know if the Dodge would have the connection issue without incandescent bulbs in the brake circuit for loads.

[Bauxter]

Zep, I caught one of your how-to demo's at the Resto Rally a couple years ago. If you still attend and teach, this seems like a really interesting and useful topic. I have learned to weld, work on windows, and work aluminum, but looking at your diagram above, my eyes glazed over...quickly. (dont know anything about electronics)
When you say bare tail light, are you drawing a contrast to the pre-assembled ones sold at VTS? Have you posted anything on running light conversion?

Mike

[Zeppelinium]

Mike,

Some of my LED light conversions look complicated because they use a few diodes and resistors, but these cheap components can add significant usefulness to your lights and in the dim mode are perfect for mood lighting, with the added benefit of very low current drain (0.06 amps, for example).

If you're not interested in modifying your marker lights, skip the first few threads below and go to the scare light, backup lights, and interior light examples.

This is one example of how to wire your marker lights for low current draw and make them switchable from inside the trailer without interfering with normal operation from your tow vehicle. http://www.airforums.com/forums/f447...ts-100174.html

I don't know why I did the following conversion of the marker lights (making them easily replaceable--I like the dimming capability and the ease of turning them on when parked). These LEDs should last forever.
http://www.airforums.com/forums/f421...ml#post1080374 and post 122 in the same thread.

using exterior lights for other purposes (party, party): http://www.airforums.com/forums/f421...ml#post1090885 I have been using the marker lights to give the impression that I'm on the property where I'm building a new house. I can leave them on for a week before I need to think about the battery.

one photo of a new LED in the Overlander as a reading light over the bed: http://www.airforums.com/forums/f169...ml#post1177151

LED backup lights: http://www.airforums.com/forums/f447...ts-101012.html

Post 14 and 24 here show a particularly useful addition over the front window and modification of the over-door exterior light. You can see the addition of the new light in post 39. I am happy not to have the standard "scare" light any longer.

Here's another conversion of the over-door light and others.

There are several conversion examples here, starting with the goucho spotlights.

And just one caution about LEDs that don't dim well, here.

Zep

PS--I did teach two classes on LEDs at the last Resto Rally. I had the '73 Safari there as an example.