Trailer Wiring

wallydc2

Petty Officer 2nd Class
Joined
Aug 31, 2007
Messages
103
I rewired my trailer and for a while it worked fine, now the passenger side tail light does not flash when the right turn signal is turned on nor does the brake light work. The light does come on when plugged in. Does anybody have any idea why the light works but does not function properly? And yes the right vehicle turn and brake lights work. Any help would be GREATLY appreciated.
 

wallydc2

Petty Officer 2nd Class
Joined
Aug 31, 2007
Messages
103
Trailer Wiring

I rewired my trailer with a new led light kit and for a while it worked fine, now the passenger side tail light does not flash when the right turn signal is turned on nor does the brake light work. The light does come on when plugged in. Does anybody have any idea why the light works but does not function properly? And yes the right vehicle turn and brake lights work. Any help would be GREATLY appreciated.
 

mla2ofus

Chief Petty Officer
Joined
Dec 30, 2008
Messages
571
Re: Trailer Wiring

Sounds like a connection problem somewhere between the light and the tlr plug or check to make sure the right turn post on the tow vehicle receptical is hot while tow vehicle turn signal is on.
Mike
 

wallydc2

Petty Officer 2nd Class
Joined
Aug 31, 2007
Messages
103
Re: Trailer Wiring

How do I test the vehicle? I have an electrical tester do I just set it to 12v DC and stick the red lead in the plug?
 

Bass Tracker TX17

Petty Officer 1st Class
Joined
May 26, 2008
Messages
253
Re: Trailer Wiring

I rewired my trailer with a new led light kit and for a while it worked fine, now the passenger side tail light does not flash when the right turn signal is turned on nor does the brake light work. The light does come on when plugged in. Does anybody have any idea why the light works but does not function properly? And yes the right vehicle turn and brake lights work. Any help would be GREATLY appreciated.

Brake and turn use the same circuit on the trailer. I would double check your trailer connector and trace back. Make sure you have power on the vehicle side to be sure. If your vehicle is using a control box, we see them take a dump all the time and will give you strange results. So once you confirm your output to your connector from your vehicle is ok then attack the trailer.
 
G

Guest

Guest
Re: Trailer Wiring

From my experiance I would look at the bulb first (filament might have broken and touched the other part of the filament then the wire conections from the plug right to the tail lights and while ur at it double check the grounds at all the light fixtures as well.




If you stand there looking at something for a while someone might just come along and fix it for you! :rolleyes:
 

kmarine

Chief Petty Officer
Joined
Nov 5, 2010
Messages
591
Re: Trailer Wiring

Try cleaning connectors or wiggle them. I have had surface corrosion occur in a couple of months. I like to use a little grease to keep out the weather.
 

mike343

Petty Officer 1st Class
Joined
May 4, 2009
Messages
284
Re: Trailer Wiring

I'm confused. Post says right turn/brake doesn't work and then it does. And what does "plugged in" mean?
You symptoms are consistent with a broken wire or bad connection on the right turn/brake line, Measure the voltage at the truck side connector as a first check.
 

wallydc2

Petty Officer 2nd Class
Joined
Aug 31, 2007
Messages
103
Re: Trailer Wiring

The right light comes on (trailer) when plugged in but the break light nor the turn signal works. Turn signal and break lights work on the vehicle.
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,771
Re: Trailer Wiring

There are two filaments in a trailer lamp (sort of like two bulbs in one). When you have the normal running lights on, the dimmer of the filaments is lit which I gather is what you mean the light is on when plugged it. However, the stop and turn signal uses the other filament which is the brighter of the two. The circuit for that filament (not the brown wire) is not connected somewhere along the line, the bulb is bad, or the right turn signal on the tow vehicle wire harness is bad.

To test the tow vehicle, set the meter to read 12 volts. Connect the black test lead to ground and place the red test lead on the right turn terminal on the harness. With the signal light on, the meter should show voltage, then off, then voltage then off (sort of a yup - nope scenario).
 

richock

Seaman Apprentice
Joined
Oct 5, 2009
Messages
46
Re: Trailer Wiring

This might not seem relavent, but what kinda tow vehicle?
 

jeeperman

Lieutenant Commander
Joined
Aug 2, 2001
Messages
1,513
Re: Trailer Wiring

What type of lights?
Post a link to the kit you installed.

If you have the dual filament incandesent bulbs like Silvertip described...............
On some trailer light fixtures
Check to see that the bulb is seated properly, it may have un-twisted itself due to vibration. Especially if it was close but not turned to the proper position to begin with. You can still have tail lights with the bulb just hanging in the socket.
Also check the bulb base for corrosion on the two positive contact spots.
As well as the brass contacts strips they are suppose to touch.
Also check the wires going into the housing. Sometimes the ones with friction grip "push-in-the-wire" thingy does not do the job good enough.
Especially if the wire ends were not twisted and tinned upon install.
 

sqbtr

Senior Chief Petty Officer
Joined
Feb 23, 2010
Messages
716
Re: Trailer Wiring

This might not seem relavent, but what kinda tow vehicle?

I would call this a very revelent question, all newer trucks have seperate trailer circuits. IE check the under hood fuses.

Forget the meter, get a test light and check the basics. IE KISS, bulbs blow all the time
 

sqbtr

Senior Chief Petty Officer
Joined
Feb 23, 2010
Messages
716
Re: Trailer Wiring

If one side works its not a fuse.

Actually there are seperate left and right turn fuses.

But the OP has not stated what tow vehicle he has
 

Shrike

Petty Officer 2nd Class
Joined
Jul 17, 2009
Messages
112
Re: Trailer Wiring

Actually there are seperate left and right turn fuses.

But the OP has not stated what tow vehicle he has

Thats a new one on me.
But my newest vehicle is 10 yrs. old.:D
 

Frank Acampora

Supreme Mariner
Joined
Jan 19, 2007
Messages
12,004
Re: Trailer Wiring

Gentlemen: You are missing the fact that he said he has rewired with LED.

I can't help because I have no experience with LED lighting.

He stated it worked fine for a while now it does not. IMHO: That usually sounds like a ground problem.
 

jeeperman

Lieutenant Commander
Joined
Aug 2, 2001
Messages
1,513
Re: Trailer Wiring

LOL,
Shoulda read the second post instead of assuming it was a duplicate post.
 
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