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need help re trailer lighting

R

rich

Please help me if you can. If I understood the internal workings of a 1157
bulb..I'd feel better about this issue..

I have a trailer with .....wired ground leads with white wire ground to the
lights individually (I moved my trailer lights to the top of PVC uprights,
and since PVC doesn't carry electricity, I added separate wired grounds)..
That part seems to work OK since I have working stop and turn lights on both
sides. I don't have parking lights.... Yellow and brown to one side, green
and brown to the other side... All SHOULD work normally.

The replacement rear light has.... RED and BLACK wires coming out of it.
It IS designed for stop/parking/turn operation. I added a white ground wire
to the base of each unit and connected that back to the white wire ground
from the wire harness. . I ASSUMED that the BLACK wire would match the
BROWN wire and I wired accordingly... My issue is the lack of parking
lights.

After thinking about things for a while, I wondered if the BLACK should be
connected to the green or yellow wire .... and the RED wire should be
attached to the BROWN lead???

A little further confusing thoughts...that the colors, by themselves,
shouldn't mean anything...one filament should be on "all of the time" ( when
the parking lights are set to ON)..and the other filament should be on/off
based on input from the relay on the left or right sides.

Why, then, doesn't the "wrong" connected filament at least "glow" when I
may have mistakenly reversed the wiring??? I then wondered if the filament
on the BRAKE/TURN INDICATOR side is so much bigger..that it doesn't reflect
any "glow" even though current is flowing to it..

I'm puzzled. I hope the above description comes close to explaining the
issues and my thoughts about them...Thanks for any observations and or help.

p.s I know I could just switch the two leads and I probably will do that
the next time I go to the boat...but the issue of a non-glowing filament on
....even the wrong side... still puzzles me.
thanks, RichG TX/IL
 
L

Larry

Please help me if you can. If I understood the internal workings of a
1157 bulb..I'd feel better about this issue..

You assumed wrong. The 1157 has two filaments....one for STOP/TURN and
one for parking/taillites. It's made for American cars that share stop
and turn bulbs in one light.

Your vehicle has 3 circuits, separate stop and turn lights. Trailer
manufacturers and trailer light manufacturers still think this is 1949
and everyone's boat is being pulled by a Plymouth or GMC pickup, not a
Jap SUV.

So, what you need is the proper trailer light adapter for your
vehicle....and they are ALL DIFFERENT!

Still pissed about losing WW2, the Japs are getting even by using a crazy
arrangement for these taillights in their vehicles. Instead of switching
power to the bulbs....like normal humans....oh, no, they're switching
GROUND!, leaving the bulb hot on both sides. This, of course, requires
you to buy an expensive electronic module, like everything else in the
damned SUV to operate the trailer lights.

I went through this with a friend trying to get a trailer hooked to a
Honda SUV. He had to shell out for a special converter module, about
$90, to get this crazy taillight nonsense Honda has to light up simple
trailer lights. They're switching GROUND! Of course, Japanese cars were
all POSITIVE GROUND until Americans said they wouldn't buy them that way.
Wrong polarity, wrong driver position for American tastes.

What vehicle are you using? We'll have to know that to figure out which
module you'll need....(sigh)

http://www.drawtite-hitches.com/electrical/modulite.htm

Oh, by the way, let me warn you. These lights are NOT connected to
simple switches or relays in many vehicles, but to the MAIN COMPUTER
WHICH CAN EASILY BE DESTROYED AS YOU SCREW AROUND TRYING TO HOOK UP
TRAILER LIGHTS and short something to something or hook ground to what
you THINK is ground! Be forewarned if you try to play games without the
proper module, you may be buying a computer that makes your desktop
computer layout look like buying a ham sandwich in comparison. Car
computers are priced like the gas they burn......
 
R

rich

Hmmmmm Maybe I could just tie a red flashlight to the stern of the boat to
make up for the missing "parking" lights....

It is a Ford 2005 Expedition. It has the "factory" module already installed
and the output is both a seven pin and a four way flat. The four way flat
is what I am using. Testing of the pins on the seven pin outlet seems to
follow the correct outputs.... as printed on the plastic dust cover. The
four way flat has been tested with a little "trailer tester" with three
LEDS. The "parking brake" LED glows brightly; and the Turn indicators ( both
L & R) glow in a flashing manner when the vehicle is set to use the turn
indicators. Everything on the auto side seems to be ok..after I changed out
one of seven ( I think ) TRAILER fuses ( the left turn indicator fuse ) in
this vehicle. After hooking everything up and having everything work (
except the parking lights) the fuse remains intact.

I think that the same Vehicle and hook-up works OK on my trailer (that is
1200 miles away in another State) with the same High PVC uprights and the
very same red/black light units attached. My foggy brain tells me that I ran
into something similar when I hooked that rig up...but I honestly don't
remember what I did to solve it.. It probably was my usual "trail and error"
and I probably reversed the two leads.

Any further help appreciated. RichG TX/IL
 
E

Edward Stammer

Having just done this task, I found out the following:

1. Make sure the gound is working by using a resistance checker and making
sure there is none/minimal between the trailer and the vehicle. Using the
hitch to ensure a good ground is iffy at best, since most people grease the
ball or the inside of the hitch to prevent wear and tear. Grease does not
conduct electricity well at all.

2. The yellow goes to the right side turn signal while the green goes to the
left side turn signal.

3. The brown goes to parking lamps only.

The 1157 bulb uses two filaments, the brighter of which is for brakes. If
you wire up the lights to have the brighter on with the parking lamps, then
you have the socket/light assembly wired backwards.

This article may also help:
http://www.popularmechanics.com/automotive/how_to_central/electrical_electronic/1272556.html

Ed Stammer
 
R

rich

Well, I thought I had it figured out. Today I went to the boat and switched
the red/black wiring. STILL no parking lights. Next time I go to the boat,
I am going to switch out both bulbs..... who knows.. maybe both of the
Parking filaments went out at nearly the same time, though both filaments
appear fine..I haven't put a meter across them yet... RG
 
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