Trailer Light Problems

[Wellcraft170]

Went out the other day to test all the lights were working cause im taking the boat to the lake this weekend. Nothing was working except the running light on the right side of the trailer. I've went through everything through diagnosing the problem switched out the main wiring going to each side of the trailer, a new harness, even purchased new lights....still only have a running light on the right side... the ground is grounded to the trailer. i also just got the wiring set up in my car last month. any suggestions? cant drive 3 hours north without any lights

 

[Leardriver]

There is no magic recommendation.
Hook up the trailer light plug to a power source, such as the tow vehicle, turn on the parking lights, get a test light, and test for power to wherever you are questioning power availability. If none is present, back track to where you do have power. Figuring out if your lights work sort of takes care of itself if you verify power and ground.​

 

[alldodge]

Its either the trailer or the truck. Running lights on one side is controlled by the brown wire and it covers both sides of the trailer. Your only seeing one side so there is a bad connection and I'm thinking your connector

 

[meder24]

I had a similar problem before where only my Left side lights would work. I too had my lights grounded to the trailer. I got rid of the trailer ground and just wired the grounds directly to the ground on the plug from my vehicle. After that, no more problems. Bad grounds are common issues.

 

[Maclin]

Did they work right after you got the car setup? What kind of car, who did the setup.

 

[Wellcraft170]

Did they work right after you got the car setup? What kind of car, who did the setup.

local mechanic installed it once i got the car about 2 months ago.

 

[Wellcraft170]

I had a similar problem before where only my Left side lights would work. I too had my lights grounded to the trailer. I got rid of the trailer ground and just wired the grounds directly to the ground on the plug from my vehicle. After that, no more problems. Bad grounds are common issues.

i was thinking of that..howd you connect the ground to the plug from your vehicle? just spliced it?

 

[Gary H NC]

I would look at the wiring on the tow vehicle.......Something is not right there.
A test light or multi-meter should find the problem.

 

[MH Hawker]

No Title

i suggest starting with this

http://www.harborfreight.com/four-way-trailer-light-tester-66526.html

 

[Illinoid]

Keep your hat on...I think after half a century of dealing with these problems...I seem to have pulled all my hair out. Every time I get cocky and think all trailer problems are simple and I have seen it all I get one that takes me a few hours to figure out and fix.

 

[Maclin]

local mechanic installed it once i got the car about 2 months ago.

What kind of car.

 

[meder24]

i was thinking of that..howd you connect the ground to the plug from your vehicle? just spliced it?

I just wired all of the ground wires on the lights themselves directly to the white wire coming from the trailer plug.

 

[Wellcraft170]

What kind of car.

2009 dodge nitro 4x4

 

[meder24]

I used to have a Nitro myself. When I installed my trailer wiring harness, I had some issues with the connectors to stock tail light bulbs. For some reason, the connectors in the harness would not fully engage the stock bulb plugs on the vehicle. Unlikely to be your issue, but something to confirm is secure.

 

[Bkok33]

I had a problem with my ground wire, checked it and regrounded it. Works better now. How old is the trailer? Maybe it needs to be rewired.

 

[Outkast]

Hello there, I do this for a living I'm a trailer mechanic and a Draw-Tite hitch pro. first question, did the mechanic who installed your trailer lights just tap into your lights or did he use a powered module? Nitro's need a powered module they don't produce enough amperage to power a trailer and it's self. How you can tell is under your hood you should see a yellow or red (if it's a Curt wiring kit) fuse holder. Second, dose the flat 4 plug on the trailer have one or two brown wires, if it's one follow it back it should then split into two it maybe that connection. Could also be just you lights if they're 194 bulbs they are notorious for the sockets going bad, and yes double check your grounds. Hope this helps.

 

[Wellcraft170]

Hello there, I do this for a living I'm a trailer mechanic and a Draw-Tite hitch pro. first question, did the mechanic who installed your trailer lights just tap into your lights or did he use a powered module? Nitro's need a powered module they don't produce enough amperage to power a trailer and it's self. How you can tell is under your hood you should see a yellow or red (if it's a Curt wiring kit) fuse holder. Second, dose the flat 4 plug on the trailer have one or two brown wires, if it's one follow it back it should then split into two it maybe that connection. Could also be just you lights if they're 194 bulbs they are notorious for the sockets going bad, and yes double check your grounds. Hope this helps.

thanks for the tips. i'll try it again in a few days. i originally thought it had to be something with the wiring set up in the car. I re-wired the trailer, and got new lights just to see if it was the actual lights themselves and it wasnt. I tried a different extender wire, and also tried a different car, maybe ill try working with the ground wire. all i have is the right light working on a solid running light. thats all that works

 

[Tony T.]

I had wiring problems last year 2015 and discovered it when I bought my Tracker boat, after making the boat deal I hooked up the trailer and had lights all around except the boat trailer left light on back would not work. The guy I bought the boat from said man I just pulled it home from our lake lot this weekend and all lights were working fine. Long story short the problem turned out to be in my truck 2003 Dodge Ram . Mechanic buddy of mine spent over 3 hours tracing the wires from the 7 pin plug in all the way to the fuse box under the hood,he didn't have a wiring schematic either which was a pain in the rear and the color code changed about 3/4 of way through the trace. Turns out he had to replace my fuse box under the hood to fix the problem, and he used a fuse box from a salvage yard, it cost $100 bucks for that used one, he told me last one he bought new and he didn't specify if it was for a Dodge was around $700 bucks. Man I'm glad the used fuse box worked, it's fixed now. I have 3 trailers I pull and the same light left back on each trailer was the one that would not work before he fixed the problem.


Tony