brake lights & turn signals work but not running lights, which color wires are they?

exnavyman123

Petty Officer 2nd Class
Joined
Apr 17, 2010
Messages
123
brake lights & turn signals work but not running lights, which color wires are they?

brake lights & turn signals work but not the running lights, which wires are they or how can i diagnose?
 

Bob's Garage

Chief Petty Officer
Joined
Apr 10, 2008
Messages
590
Re: brake lights & turn signals work but not running lights, which color wires are th

Re: brake lights & turn signals work but not running lights, which color wires are th

What is your tow vehicle? Have they ever worked? Are they incandescent or LED? The yellow is the left, green is the right and brown is for the running lights, white is the ground.

You should start by verifying that the plug is working at the tow vehicle. This can be done by using a volt/ohm meter, a test light or a test plug with LEDs.

If everything checks out, then you need to trace the wires looking for breaks. One of the things I do is use a straight pin, stick into the conductor and check for voltage with a volt meter. Then seal the pin hole with fingernail polish. If you look you will find it.

Good luck, and I am sure there will be advise contrary to mine.
 

sw33ttooth

Chief Petty Officer
Joined
Apr 24, 2011
Messages
498
Re: brake lights & turn signals work but not running lights, which color wires are th

Re: brake lights & turn signals work but not running lights, which color wires are th

yah, white is bolted to the trailer or wired to each light black is your running lights and side markers[also may be brown] then green and yellow are blinkers. most times after winter the salt corrodes your vehicals plug every 2-3 years needs replacing and often cleaning twice a year depending on if you live in a snowy area.

hello jhebert, nice to see a fellow michigander on here few and far between :)
 

can-amsledder

Petty Officer 2nd Class
Joined
Jul 14, 2009
Messages
140
Re: brake lights & turn signals work but not running lights, which color wires are th

Re: brake lights & turn signals work but not running lights, which color wires are th

Don?t overlook the fuses in the tow vehicle, if equipped. My truck has a separate fuse for both the trailer running lights and the brake/turn signals.
 

sw33ttooth

Chief Petty Officer
Joined
Apr 24, 2011
Messages
498
Re: brake lights & turn signals work but not running lights, which color wires are th

Re: brake lights & turn signals work but not running lights, which color wires are th

when i blow the trailer plug fuse i have no speedo 95 f 150. differnt vehicals are equipt diferntly so double check them as well takes 2 minuties to find and check replace if bad.
 

Boating Chuck

Recruit
Joined
Jul 2, 2011
Messages
1
Re: brake lights & turn signals work but not running lights, which color wires are th

Re: brake lights & turn signals work but not running lights, which color wires are th

Hey, thanks for the help guys!! I spent hours trying to track a short on the trailer, when all the while it was a blown 15amp fuse in the fuse panel under the hood. 2007 Avalanche LTZ. All of the trailer fuses are under the hood in a fuse compartment for this truck. Thanks again, now I don't have to worry about launching early tomorrow!!
 
G

Guest

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Re: brake lights & turn signals work but not running lights, which color wires are th

Re: brake lights & turn signals work but not running lights, which color wires are th

White- ground
Green- right signal (the R in green stands for right side)
Yellow- left signal (L in yellow stands for left side) both these examples left and right are easiest to remember for the wiring challenged people :confused: :facepalm:
Brown- tail and marker lights
And if you have drum/disc surge you can also have a blue wire that operates the backup bypass on the surge cylinder so the brakes don't lock up when backing up on level ground to launck boat or park the trailer.
Above all make sure your vehicle plug is wired right and you have a very good ground from it, if not you will get a lot wierd things happening with the lights such as bright signal bulb and markers lighting up at the same time AKA feed back looking for a ground
 

exnavyman123

Petty Officer 2nd Class
Joined
Apr 17, 2010
Messages
123
Re: brake lights & turn signals work but not running lights, which color wires are th

Re: brake lights & turn signals work but not running lights, which color wires are th

Thanks for all the help guys, it turned out to be a corroded ground, bad ground under the trucks light where the wires ran back to back of truck for the trailer. bought a 12v test light and tested at the pins in the plug to find which pin was running lights and not lighting up and tried different things til it did, turned out to be just as useful as my multimeter

Thanks again just wanted to thank yall, was fixed for awhile now .........
 
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