However, I am going to reference
everything in this article to 12VDC. This will give
us consistent numbers and give us a slight safety
factor. Your final install will pull a little less current.
So you want to convert those energy guzzling
running lamps of yours to the new LED’s? It’s a
fairly easy process, but do your homework before
you start spending bucks. This article will help.
Lets get two items out of the way so we can
explain things more clearly. The first is your
voltage supply. We call it 12VDC. That means 12
Volts Direct Current. DC means that the current
flows in one direction only, from Negative to
Positive. But we actually run on a slightly higher
The second is how lights are identified. As you
know, all bulbs have standard numbering. You can
go into any parts store and ask for a 1157 lamp for
your taillight. It doesn’t matter what company
makes the lamp, you will always get a 2-filiment
tail/stop light lamp rated at 5/20 watts. The same is
true with truck lighting fixtures. You can go into
any parts house and ask for a model 44 (which is
that 4" standard round fixture you see on most
trailers) and it will be the same fixture, no matter
who makes it. I point this out because this article
does not deal with the LED conversion lamps. It
deals with the sealed units that replace an entire
That being said, The Cruisers running lights are
a Bargeman or Reflectolite 278. These two fixtures
are so exactly similar, I believe they were manufactured
by the same company and marketed by
different companies. The 278 is a fairly cheesy
fixture, but it is cheap and that is why the RV
builders use it. It’s 2 worst problems are that it is
poorly sealed from the elements and it’s very sad
wiring connections. The spring clips they use are
quick-and-dirty to install, but the road grime
quickly corrodes them and makes for a poor connection.
There is no direct LED replacement for the
278 nor is it a trucking industry standard number.
The only reasonable
fixture to replace the
278 is the Model 19.
The 19 is made by all
the major lighting
Trucklite, Petersen, etc.
The Model 19 is physically the same size and
uses the same mounting hole dimensions as the
278, so no new holes need to be drilled. It has the
same “footprint” as the 278 but the domed lens is
a more rounded shape. There are 7 amber running
lights in the top front and 2 amber running lights
on the front sides of the Cruisers. Adding the 7
rear red fixtures brings the total fixtures up to 16.
If you plan on adding more, count them in.
The 278 uses a #57 lamp rated at 3 watts.
This lamp bench tested at .26 amps current draw,
just about right for a 3watt rated lamp. This totals
out to 4.16 amps required to drive the running
Before I delve into the requirements of the
Model 19, let me explain something about LED
fixture manufacture. There is no standard. One
manufacturer may put only one led in a fixture,
while another may put 4. There is a proposal
called the “PC Standard” before the Department
Of Transportation, but it has not been accepted
yet. The PC Standard calls for a minimum of 4
LEDs in the red model 19s and a minimum of 6
in the amber Model 19s. LED’s are, by nature,
coherent. That means they are very thin pencil
beams of light, like a laser. To get a wider beam
spread, they must have a dispersing lens in front
of them. The PC Standard requires a 180-degree
beam spread from all models of running lights. To
date only Trucklite is manufacturing to the PC
Standard, although it may change depending on
what the DOTies say.
I will also mention that LEDs are diodes; as
their name implies. They are one-way valves for
electricity. That means you have to hook them up
with proper polarity or they won’t work. OK,
Dale, what’s polarity? Simply the Positive has to
go to the positive and the negative has to go to the
negative. You can’t switch them like ordinary light
bulbs. To date, only Petersen Piranha series have a
circuitry that allows hook up in either way.
OK, back to the Model 19. The red Trucklite
(model 19037R) pulls .061 amps on the bench test.
It has 4 LEDs and is PC Standard compatible. The
amber Petersen (model PM161) pulls .047 amps
on the bench test. Multiplied by the 16 fixtures on
the Cruiser, this comes out to .98 and .75 amps
total respectively. This will significantly reduce the
load on your battery and your system. It is not a
cure-all. Remember, many other things come on
with your running lights, a lamp in every dash
gauge, radio, a/c controls, license lamp, etc.
When mounting LEDs, do a sample install
with one fixture first. I highly recommend buying
the mounting kit. This way you get the snap-in
mount and the pigtail connector. When purchasing
replacements for your Model 19s, it will just be a
snap (pun intended). Twist the wires together and
test it for polarity. If it doesn’t light, reverse the
wire. Check each lamp fixture before you move on
to the next. Use good butt crimps for solid connection
and stuff them back into the Cruiser’s body to
protect them from the elements. Every
manufacturer’s pig-tail connector pops into the
snap frame so they become one integral unit.
Pricing. I bought in bulk. I bought the
Petersen’s first as I was just learning about this
stuff. From my local auto parts store, I bought 10
amber fixtures for about $16.50 ea. When I installed
the Petersens’ I was disappointed at the
beam spread. Standing directly in front of the
vehicle was OK, but as soon as I moved slightly
off to one side, they appeared very dim. As I
learned more about the PC Standard, I bought the
red ones from Trucklite. My vendor was a favorite
truck supply house in San Jose, Universal Fleet
Supply. Surprisingly they cost less, about $15.00
per fixture. The trick here is to buy in bulk: the
units that come in simple plastic bags. Don’t buy
the carded units; the packaging is what costs more.
I have sent a copy of this to the people at UFS, so
if you want to call them and tell them you are with
the Aero Cruiser club, they will know what you are
talking about. I would also like to add that it is
wise to have a good truck supply house, besides
your auto parts store. Truck supply houses have
heavy-duty switches, truck seats, plugs and many,
many other items we can use.
My e-mail is below; feel free to ask any questions.
I will try and be at Chula Vista, but it depends
on my work schedule. I have also included
Return to the Tip List.
Universal Fleet Supply. Kurt or Dave 1733
Rogers Av, San Jose, CA 408/436-6060
http://www.truck-lite.com bulk pack # 10937R
http://www.grote.com next to Trucklite, one of the
http://grandgeneral.com their fixtures are kinda
cheesy but some very innovative LED stuff
http://ledtronics.com raw LEDs and some interesting
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