www.iFourWinns.com

Not super knowledgable about trailer lights, so I thought I'd throw it out to the audience. My right trailer brake light will not light. All the other lights work fine. I get a blinker light when I flip the right turn signal, and I also get a nice steady red glow when I flip on my headlights. So what gives? Am I having an adapter issue on the vehicle side or do we think it is a wiring problem. Thanks in advance for any help.

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2008 H200SS w/ 5.7L VP Gi
2009 GMC Yukon

Former Boat:
2008 H180 w/ 3.0L VP

LED's or incandescents?

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Mike
2005 Four Winns 230/240
VP 5.7GXi/DP
1998 F-150 XLT
Boat Pic

On a 2008 trailer, it is most likely LED...mine was.

You need to start at the front and work your way back with regards to checking voltage at the vehicle side pins, then the trailer side pins. and of course end at the light.

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Current Boat:
2004 Sea Ray 320 Sundancer "Nauti Luvin'"

Previous Boats:
1999 298 Vista "Seas The Day"
2008 H200SS "Nauti Luv"
2006 Tahoe Q4

+1 and don't forget the grounds! Most of the time, I have found this to be the issue.

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1992 Baja 38 Special Twin 502 Mags

03 Stingray 3.0
88 261 Liberator 460 King Cobras
95 Bayliner 1850 3.0
77 Fiber Form 20ft 350/385hp
70 Wescraft 1800 SS 455 Jet

Lead, Follow, or get the Hell out of the Way!

Yep...grounds grounds grounds......getcha every time!

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Current Boat:
2004 Sea Ray 320 Sundancer "Nauti Luvin'"

Previous Boats:
1999 298 Vista "Seas The Day"
2008 H200SS "Nauti Luv"
2006 Tahoe Q4

+3 grounds

My right brake and guide pole would not come on. Sometimes the whole trailer would not light. I had changed out all lights to LED and checked wiring. The trailer gets a ground from the white wire and coupler. When I put a new clean coupler, presto all lights, including the right were working. I used to scrub and clean the old coupler and ball and hit was hit or miss. I could usually get them going, but never the right.

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2010 Sea Hunt Triton 220 "Big Whiskey"
2003 FW Freedom 180 Volvo Penta 4.3GL/SX-M "It'll Do Four Now" (Sold)
2012 Avalanche LTZ 4X4

FW hadn't switched to LED's for very long by 2008 so wasn't sure. +4 ok the grounds, except that the tail light housing has a single ground wire and the other functions in that housing are working fine. Seems like either a bad wiring connection or a bad light to me.

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Mike
2005 Four Winns 230/240
VP 5.7GXi/DP
1998 F-150 XLT
Boat Pic

This is not very technical, workmanlike, and is not a long-term fix but have you tried jiggling the plug while checking this? Might indicate whether your issue is in the light or at the plug (such as the ground to the coupler), though. Has worked for me to diagnose it.

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Paul
2007 Four Winns Horizon 220
Mercruiser 350 Mag MPI w/ Bravo III Drive
2004 Ford Explorer Limited (V8-AWD)
Pomme de Terre Lake (Southwest Missouri)

Thanks for all of the replies! I believe they are LED's, but not certain. Is there any easy way to tell? Will definitely check out the ground situation. I did a google search last night and found a few people that seemed to have had the same problem and traced the issue back to a bad flasher relay under the dash of their trucks. The logic used (and verified by solved problems) by these folks was that if you were getting turn signal lights but no brake lights on a side it had to be an issue with the vehicle as the trailer uses a single wire/bulb/connection for both of these functions. Can anyone confirm that this is true on our trailers? I plan on doing some troubleshooting over the weekend, will probably start by checking the signal at my Trailblazer's harness w/ a voltage meter. Thanks again.

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2008 H200SS w/ 5.7L VP Gi
2009 GMC Yukon

Former Boat:
2008 H180 w/ 3.0L VP

Had the same thing on my Tahoe. A ground wire took a rock or something and cut it in two. This was a factory wire up under the back above the bumper and below the tail light. When I had flasher relay problems in the past with trucks, they would blink very fast as they had more load than rated for. They make different one's for trailering and not.

_________________
1992 Baja 38 Special Twin 502 Mags

03 Stingray 3.0
88 261 Liberator 460 King Cobras
95 Bayliner 1850 3.0
77 Fiber Form 20ft 350/385hp
70 Wescraft 1800 SS 455 Jet

Lead, Follow, or get the Hell out of the Way!

You probably do have LED's. If you aren't positive which you have, it's kind of hard to describe the difference in appearance. The light produced by LED's is brighter, more harsh, and they go on and off instantaneously because they're actually an electronic device as opposed to a wire filament that has to heat up and cool off. If you've ever been behind a newer model car at night at a stop light and thought their tail lights were especially bright, even too bright, they were probably LED's. Incandescent lights look more natural, aren't as bright, and take a fraction of a second to go on and off.



That's true, and a good point.

You might put your volt meter on pin 6 on your trailer connector (truck side) and see what you get there when you apply the brakes (alluding to Paul's suggestion).



But the more I sit here and think about this, the more I also suspect the flasher, even though I've never in 33 years of driving heard of one failing.

Faulty grounds are the source of 99% of trailer light problems, but I don't think it's the case this time. That light housing has a single ground connection to the frame of the trailer, and all the other functions in that housing are working.

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Mike
2005 Four Winns 230/240
VP 5.7GXi/DP
1998 F-150 XLT
Boat Pic

Had this happen once and it turned out to be the ground for the right light. Make sure that connection is tight.

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-Rob.


Current boat: 2011 Yamaha AR210
Previous boat: 1998 Horizon RX 4.3GL SX