Rewiring flatbed trailer

[meridien]

I'm in the process of rewiring the flatbred trailer I use to haul my L3301. I'm adding some side marker lights, amber/red lights on the tops of the fenders, and installing a breakaway system.

My question is regarding the ground. On boat trailers I've owned, I rewired them and ran a separate ground wire rather than relying on the frame for ground. Over time, being in and out of the water, you will get corrosion that can cause a ground to fail.

My flatbed is welded, so that corrosion isn't an issue. Should I run a separate ground, or tie the light grounds to the frame?

Suggestions? Wisdom pro/com?

Thanks in advance.

 

[Dieseldonato]

Depends on the lights your using. If there's a ground wire to hook up, then I'd hook it up. Never was a fan of the lights that use frame ground through a bolt/screw hole. My deck over had the latter and it's a constant pain, my other trailer didn't have much for lights on it, and the lights (led) I got as replacements had ground wires. (3/4" grommet mount.)

 

[Code2medic]

I just redid a horse trailer. I used a mainMy junction box that everything tied into on spot even the 7 pin harness and then grounded it to the frame.
Like this one turned out great considering i never reqired a horse trailer before. Replaced every light on it to Led inside and out.

fyi you can get the wire one a spool that has the colors you beed all in one pull. The leds only have two wires red and black

Conntek 7-Way Trailer Cord and Junction Box https://a.co/d/8zA7Yyj

 

[GreensvilleJay]

The last 3-4 'tractor hauling' trailers I built, I installed those '8 way plastic junction boxes' at BOTH front and rear, used 6C cable,inside 1/2" poly pipe to interconnect( have a 300' spool of it...). Having one in the rear allows for short wires from lights to rear junction. I solder/htshrink light connections(3 leads) INSIDE their housings, then use spade lugs inside the rear box. Never had a problem with using the frame as ground. One 'trick' is to HAND tighten the mounting/ground screws of the lights. It's way too easy to over stress(rotate and stretch) when using a cordless impact.

 

[NCL4701]

I’d run a separate ground wire if at all possible.

It’s just more reliable in my experience and I prefer working with my equipment more than I enjoy working on my equipment. I know others may have different experience or thoughts. While I respect what experience or thoughts others may have, it’s one of those things where I have enough real life experience with both setups that my mind isn’t changing on that topic.

 

[GreensvilleJay]

Whatever you do be sure the wiring is up close to the frame,well secured and/or in conduit to prevent 'something' from ripping the wires

 

[Yooper]

Ground wire back to the plug is best. But if you use the frame, grind the area to clean metal and use a star washer in between the terminal and the frame. I will also coat the connection with silicone sealer to prevent moisture getting in contact with the terminal. Shrink tube is your friend at the terminal to wire connection

 

[Russell King]

For sure you “need “ a ground wire from the tow vehicle connector across to the trailer-do NOT use the ball as that connection.

I would personally run a ground wire to each light and not use the frame as the only ground path.

A lot of the newer marker lights are in plastic housing and will require a ground wire to be connected.

 

[Tughill Tom]

If your using LED lights, you should run a ground circuit/wire. It will prevent problems down the road.

 

[meridien]

The consensus seems to be that a separate ground wire, rather than using the frame, is best. The lights will all be LED this time around. The side marker lights are round 3/4", the tail/brake/turn are the normal type, and the amber forward, red rearward lights on the fenders are LED as well.

I've never used the hitch ball as a ground, never heard of anyone doing that.

What surprised me about this refit, is that the law requiring a breakaway system was put in place in 2005, yet this trailer was built in 2017 and did not have one. Also, the id lights at the rear (3 lights in the center of the trailer) that are required when the trailer is over 80" in width, were not installed.

I don't really think DOT will care too much about those things on a non-commercial trailer, but still - I think they should have been installed so I'm making sure the trailer is properly equipped.

 

[Tughill Tom]

The consensus seems to be that a separate ground wire, rather than using the frame, is best. The lights will all be LED this time around. The side marker lights are round 3/4", the tail/brake/turn are the normal type, and the amber forward, red rearward lights on the fenders are LED as well.

I've never used the hitch ball as a ground, never heard of anyone doing that.

What surprised me about this refit, is that the law requiring a breakaway system was put in place in 2005, yet this trailer was built in 2017 and did not have one. Also, the id lights at the rear (3 lights in the center of the trailer) that are required when the trailer is over 80" in width, were not installed.

I don't really think DOT will care too much about those things on a non-commercial trailer, but still - I think they should have been installed so I'm making sure the trailer is properly equipped.

Brakes on both axels? If not that's why no breakaway was required.

 

[meridien]

FMVSS section 393-43 disagrees with you on that point.

I don't see any mention of brakes on both axles as an exception.

 

[Dave_eng]

One change I make when wiring trailers is to switch to marine stuff because each strand is tinned.
Normal trailer wiring allows oxygen to pass through the insulation and over time the copper wires turn black. If you then try and solder them you have a very hard time.
Tinned wire at Amazon
Dave

 

[GreensvilleJay]

Here in Ontario, mfrs 'skirt' the trailer laws by selling trailers rated for 2990#, the 'magical' number. Legally no need for brakes on the trailer, even though trailer has 3500# axle(s). However if the trailer HAS 2991# of 'stuff' on it and pulled over the driver can get a ticket as there are NO brakes on the trailer !

As for the separate ground wire per light, not needed as usually mounting screws to frame provide ground, so a 'home run' wire isn't needed. If the light has a white wire and you do 'home run' it, when a stick snags and breaks the wire, that light won't work.

Used to strip, tin, crimp, solder, heatshrink every connection for zero 'electrical' problems later on. Everyone has their way of 'wiring', I prefer to do it ONCE. When others bring me their 'problem', I gut 100% of the mess, install all new wiring, lights, etc. as it takes far less time than troubleshooting.