Trailer Light issue

5/30/14 @ 11:28 AM
ORIGINAL POST
taclbx1
taclbx1
USER since 6/16/10
Looking for some help. Installed New LED trailer lights last fall. All worked fine. Now I have tail, signal and brake on the left side and only Tail and signal on the Right side. Wiring all looks good. Could the light itself just be bad? Thanks in advance for all your responses Smile
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Displaying 1 to 10 of 10 Posts
6/1/14 @ 7:21 AM
Plmlk
Plmlk
MEMBER since 12/18/07
Just started last year dryice. Going in and out of the water so much it doesn't take too long for the connections to get corroded.

Probably should have started using it years ago...

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5/31/14 @ 11:14 PM
dryice
dryice
MEMBER since 12/7/04
ifish and pimlk, do you guys use, recommend lithium grease for electrical marine connections? I heard it helps prevent corrosion and helps maintain connections. Any feedback?

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5/31/14 @ 8:48 PM
Brother of the brush
Brother of the brush
USER since 1/22/12
If your brake lights work, the signals should work also and vice versa. On newer vehicles, there's a fuse for left turn, right turn and brake. Who knows, there may be a fuse for left brake and right brake??

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5/31/14 @ 7:42 AM
ifishwi
ifishwi
USER since 1/12/05
With a basic 4-flat plug I don't think there is even an opportunity to have the signal and brake separate. The 7-way allows this plus electric trailer brake. That makes this problem seem kind of strange, so like others I suspect a faulty ground, likely at or near the offending light.

I would also test the hazard lights with parking light on/off and see what you get.

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5/31/14 @ 7:12 AM
Plmlk
Plmlk
MEMBER since 12/18/07
A ground is always the first place to look when your trailer lights are not working. 90 percent of malfunctioning trailer lights end up being the ground.

However, since you only have a problem with one device, (right brake light) I'd suspect a wiring problem with that device or the wiring to that device. That said, because grounds are almost always the problem here is a good place to start:

*Check the ground wire (white) leaving the flat four. It leaves the flat four and connects directly to the frame of the trailer. Many times this connection gets corroded, or the pin itself breaks off in the female of the flat four. This connection is molded within the rubber - so it is easy to miss if it breaks off. Had me scratching my head for 30 minutes when it happened to me... Definitely something to look at.

*Next you need to check the right brake wiring. Go to Napa and buy a DC Voltage light. They are pretty cheap. They don't give you voltage, just light up if voltage is present. On the flat four leaving the tow vehicle the third female pin is green (right turn and brake), put the black lead of your testing light into the only male pin which is white (ground), and put the red lead into the third female pin which is green - then have somebody step on the brake of the tow vehicle and see if the light turns on. If it does you have eliminated the tow vehicle and it is time to move onto the trailer.

*Go to rear right side of the trailer and look at the wiring, make sure a connection didn't come loose. If all looks well, disconnect the wiring at the tail light. Put the red lead of the voltage light on the green wire, and the black end on the ground of the trailer, then have somebody step on the brakes and see if the test light turns on. If it does, you have a bad tail light, if it doesn't you have a wiring problem between the flat 4 and the tail light.

Edited on 5/31/14 7:12 AM
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5/31/14 @ 4:37 AM
fishs
fishs
MEMBER since 2/17/04
Get yourself a 12 volt wire tester and start at the tongue and work your way back. You'll figure it out.

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5/30/14 @ 9:04 PM
centralwiwalleyeslayer2
centralwiwalleyeslayer2
USER since 2/15/10
my bet is its a bad ground on the trailer. mine started that way this spring. was a bad ground

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5/30/14 @ 3:38 PM
Ulbian
Ulbian
USER since 9/24/03
Keep it simple as you begin your search.

Check grounds, check fuses, check connections. Most of the time it's one of those. Also check your trailer with a different vehicle and check your vehicle on a different trailer. Very quick and simple and will isolate the issue as either the trailer or the vehicle.

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5/30/14 @ 11:49 AM
BigMusky12
BigMusky12
MEMBER since 12/22/04
check your connections - mine does this sometimes after 10 years and a little wiggle of cables fixes problem. I really should take time to redo connection this weekend...thanks for reminder!

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