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trailer lights not working and cant figure out why

Old 02-04-2011, 02:35 PM
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Default trailer lights not working and cant figure out why

so I have an enclosed trailer and the stop and turn signals to not come on, but the park light do work, meaning that when i tturn the lights on thetrailer ligts do light up but i get no turn signal and no brake light,

i have baught new lights and wire and made sure I have a good ground and same thing happers,

so its got to be the truck, and how could this be its only got 2000 miles on it, not old enough for corrosion,


Help me help me, does anyone know what I can try next??
Old 02-04-2011, 03:01 PM
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fuses & bulbs? might check the pinouts on the truck where the plugin is with a volt meter to see if there is power. you'll need the blinkers & the brakes on.
Old 02-04-2011, 03:10 PM
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do your trailer lights require the constant power wire to be on? I bought a lightbar that does and it didnt work either. there is a fuse and a relay in a bag in your door or glovebox that need to be installed in the fusebox, not sure why they werent installed from factory. sadly i dont remember where they go, but if you look in your manual it will be concerning the constant power wire in the round trailer connector. There should be one fuse and one relay. they go on the right side somewehre near the back of the fusebox if you are standing in front of the truck looking at it under the hood.
Old 02-04-2011, 03:29 PM
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Originally Posted by kmac1036
fuses & bulbs? might check the pinouts on the truck where the plugin is with a volt meter to see if there is power. you'll need the blinkers & the brakes on.
+1 Easy to check your truck at the plug (where your trailer plugs in to the truck) you can buy a light tester for a couple bucks at any auto parts store (or even wallys- I have even seen them at a $ store) Just turn on your turn signal and then check al lof the pins at the plug w/ the tester. One of the pins should make the light on the tester blink if your truck is ok. Check the other turn signal and then have someone put their foot on the brake pedal and check the brake light pin the same way. Here is a wiring diagram that shows which pin is for each function. Just find the one that matches the one on your truck. Also some trouble shooting help.

http://www.etrailer.com/faq-wiring.aspx

Last edited by mikegs1952; 02-04-2011 at 03:36 PM.
Old 02-04-2011, 03:45 PM
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Some trailers use the hitch to ground. Drive the trailer around, doesn't take much and see if they come on. My horse trailer does this all the time. I drive 40 ft and lights work.
Old 02-04-2011, 05:47 PM
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well its def not the trailer, i have three trailers i tested it on and same thing, light come on but no signal and no brake, being that its new I am just gonna take it in, i belive its a ground issue on the truck side,

Thanks'
for the help
Old 02-04-2011, 05:54 PM
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Originally Posted by rogueknight
Some trailers use the hitch to ground. Drive the trailer around, doesn't take much and see if they come on. My horse trailer does this all the time. I drive 40 ft and lights work.
That's not good enough to rely on. You can see people driving around like this and every bump they hit makes their lights flash as the ground comes and goes.

All you need to do to test with the test light is turn the hazards on and the parking lights on. The turn signals for each side is the same circuit as brake lights. Don't need someone to step on the brakes this way.
Old 02-04-2011, 05:57 PM
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Like kmac mentioned, you likely need to put the additional relay and fuse located in the glove box into the main fuse box under the hood. Without it you are only running on the four pins which does not provide the turn signals. My truck was the same, once I put the relay and fuse in all was good. For some reason, these two items were not installed at the factory but were included with the truck.
Old 02-04-2011, 11:17 PM
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Originally Posted by DPatton
Like kmac mentioned, you likely need to put the additional relay and fuse located in the glove box into the main fuse box under the hood. Without it you are only running on the four pins which does not provide the turn signals. My truck was the same, once I put the relay and fuse in all was good. For some reason, these two items were not installed at the factory but were included with the truck.
it was me that said that, im 98 percent sure thats his issue,
Old 02-04-2011, 11:43 PM
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Originally Posted by DPatton
Like kmac mentioned, you likely need to put the additional relay and fuse located in the glove box into the main fuse box under the hood. Without it you are only running on the four pins which does not provide the turn signals. My truck was the same, once I put the relay and fuse in all was good. For some reason, these two items were not installed at the factory but were included with the truck.
A four way connector DOES provide turn signals.

Thanks

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