I work in the trucking industry and the lights bumper is referring to are
now in widespread use on trucks. This has brought the prices down, which
has further stimulated sales, which has brought the prices down further,
which has...

The Maxxima lights that bumper has were the best deal on the market a year
or two ago. That has changed several times since. We are currently selling
red 4" (100 mm) LED stop and tail lights for rubber mounting for under $15
U.S. each. These are Grote units, with fewer but brighter LED's. Amber
units cost more. There are also numerous styles of LED clearance lights
available now, as well as white LED back-up and dome lights.

Beyond the relatively instant time it takes for these lights to turn on,
there is also the advantage of virtually unlimited life (many are guaranteed
forever against burn-out). The biggest advantage, however, is surely the
low current draw and low voltage tolerance of these lights. When the tail
lights are perhaps 15-20 meters and several poorly maintained connectors
from the alternator and battery, traditional lights look like weak candles.
The LED lights work just fine. After all, they were designed for use at the
back of 2 or 3 long trailers.

The people in the trucking industry use LED lights mostly because they
reduce maintenance to a small fraction of traditional lights.
-Bob Korves

"bumper" wrote in message
...

"chipsoars" wrote in message
oups.com...
What LED fixtures did you use and where did you get them?

I'm also thinking about a high mounted brake light. Anyone done that?

Chip F.



Chip,

I got them from

http://www.partssystems.com/shop/pro...y_id=LED%20STT

I used the 4" round, 56 LED fixtures (you also have to order the pigtail
or
plug and a rubber gasket flange mount) for the tail/turn/brake lights. An
over unit was used for the 3rd brake light on the upper fin.

Note that since the back surface of the Cobra fin (at least on my aluminum
top) is angled forward slightly, it is necessary to make a wedge so the
fin
light fixture is perpendicular to the ground. This is because LED light
fixtures typically have a narrower beam angle than incandescent fixtures.

I used a small relay for the "logic" circuit (the NO contact of the relay
is
supplied by one turn signal and the power to the relay coil comes from the
other - - thus if both tail lights are on at the same time, the fin brake
light comes on). They sell a module for this, but it is really just a
couple
of isolation diodes. Problem with using diodes is you lose about .7 volts
across the diode. Like Eric Greenwell, I also added two side LED
turn/brake
lights right above where Cobra puts the side marker lights, but on the
clamshell part, an amber one mid-span and a red one near the rear.

BTW, the difference in light intensity and especially the "attention
getting" rise time of the LED brake lights is remarkable. My light upgrade
project was spawned by this overwhelming fear that some unwed welfare
mother
with no insurance would torpedo my trailer from behind (g).

all the best,

bumper