Grounding lights

[sphelps]

Is it best to ground the lights with a dedicated wire to the harness ? Or just connect to the trailer ? I know it's been discussed many times . Having light issues and I think it's ground related ...
Thanks for any input !

 

[alldodge]

Is it best to ground the lights with a dedicated wire to the harness ? Or just connect to the trailer ? I know it's been discussed many times . Having light issues and I think it's ground related ...
Thanks for any input !

I have less issues with lights if I use a separate ground wire. That said I have some with and without separate round wires, and the ones without the additional ground wires I have more issues with lights.

That said Many of the lights I have do not have ground wires coming off the lights

 

[lckstckn2smknbrls]

I prefer to run the ground wire down one side of the trailer and back up the other side making a complete loop.

 

[Silvertip]

The only issue with grounding at the trailer frame is many trailers have the tongue bolted to the trailer which has the potential for poor electrical connections at those joints. If you put a ground braid across those joints, the frame ground is perfectly adequate. If the frame is fully welded, then I tend to use the frame.

 

[sphelps]

I prefer to run the ground wire down one side of the trailer and back up the other side making a complete loop.

Both ends connected to the white wire from the trailer side of the harness ?

 

[gm280]

I go about this a little different then most. I run separate ground wires from each light to a central trailer ground back from the actual trailer hitch but on the trailer tongue, that also has the white wire coming from the flat plug grounded there as well. So every light is trailer grounded with the vehicle ground wire. In effect separate grounds from each light that are also trailer grounds. Never ever had any issue with grounds ever. And every wire connection is soldered and heat shrunken as well. Sounds like overkill but it works every time! JMHO!

 

[bruceb58]

If you add a separate ground wire you have just doubled the complexity. Make sure each light is grounded well and you will never have an issue.

 

[Bandaide-AL]

I just added a ground wire to my small trailer (16' boat, 18-20ft? trailer). Since I've only two combo light assemblies and no sidemarkers it just made too much sense to run the wire instead of basically having to disassemble, clean and reassemble all of the connections. $5.00 of wire and fittings. In this case, I started with 50ft of wire, folded in half and fed the fold up the front third of the trailer to the tounge, then ran each leg to the combo lights along the path of the power wires and using the same fasteners. I did wind up replacing one combo unit because the lense was missing but the other unit, I just used a dremel and brush to remove the corrosion. All work perfectly now.

 

[Willyclay]

I vote for the dedicated ground wire after chasing "ground ghosts" for many years. Not just opinion, actually have done it. Good luck!

 

[hungupthespikes]

Both. :lol:
I always try and do both, ground to the tongue, then run a ground wire loop to all lights, joining the light's ground to the wire and the trailer at the location of each light.
​Works good and gives you a test point at each light.

 

[lckstckn2smknbrls]

Both ends connected to the white wire from the trailer side of the harness ?

Yes.
This goes back to my days installing telephone wiring in new house. If you make it loop back and there is ever a break in the wiring the you won't have to open up walls to fix the wiring.

 

[gm280]

Wiring separate ground wires to each and every light with soldered points and heat shrink and joining them together at one grounding point solves a ton of possible future problems. Grounding the lights at each place they are attached can lead to so many possible bad grounding issues because you now have all those grounds attached to the trailer and therefore the possibility for corrosion to happen at each separate ground. But running separate wires all to one grounding spot make only one possible point for such possibilities. And grounding the flat plug white grounding wire with all the other grounds solves such issues... Now each wire has two types of grounds, the separate ground wire from each light and the trailer ground. And that also allows you to not even have to hitch up the tongue to verify lights will work. But you also have the frame of the vehicle and trailer as grounding points too. So even if the trailer ground gets corrosion, it is still attached to all the separate grounding wires anyway. Very good backup system I'd say! Yes it takes more wire and time, but all the years I've been trailering things, not one time did I ever have any problems...ever! JMHO!

 

[lckstckn2smknbrls]

Everywhere the ground wire touches the trailer frame is a ground point. If your trailer has 2 taillights and 2 side marker lights you have 4 grounds to the trailer. So even if 3 of the grounds are compromised you still have the 4th.
Actually there will be 5 ground points I do a ground on the tongue.

 

[bruceb58]

Been boating for over 30 years and never used a separate ground wire. If you make a good ground at the light, you NEVER have to worry about it. If you do get one light that fails, you know exactly where to look. If you get a whole series of lights that fail, you have double the troubleshooting because you don't know if its this hack ground side you put in or the positive side.

As an electrical engineer I try to make my life less complicated not make it more complicated.

There is a reason trailers do not come from the factory with an extra ground wire...they aren't needed.

 

[oldjeep]

I'll be contrary here. Any decent trailer I've owned has had ground wires running to every bulb from the factory, any cheap crappy trailer had grounded them to the frame.

This is the factory wiring on my current trailer.
http://www.boatmateparts.com/manuals...1217072303.pdf

Of the 5 trailers that we currently have, only one of them has bulbs grounded to the frame - the cheap 2 place steel snowmobile trailer. The jetski, pontoon, car trailer and my boat trailer are all fully wired from the factory.

 

[bigdee]

I vote for the dedicated ground wire after chasing "ground ghosts" for many years. Not just opinion, actually have done it. Good luck!

x2 This is especially true on bolted frames and if using LED lights

 

[H20Rat]

I'm in the 'no need for ground wires camp'... Done properly, they will work very, very well. Problem is that people often take shortcuts or just plain do it wrong. I have never once had to run ground wires on any trailer. 95% of the lighting problems I've had to track down on any system I have redone have been because of the actual wiring. That said, If I go into a problem trailer that I haven't touched, ground is the first thing I check. Either really crappy ground connections, or they used the trailer ball as a ground.

 

[bigdee]

Yes, using ball is most common for problems. Bolts are the 2nd most troublesome. I jumper across bolted frame sections and use welded studs for all ground connections. There is nothing wrong with using the frame as a ground bus if those pre-cautions are taken.

 

[sphelps]

Thanks guys for all the input !
I picked up the wire for dedicated ground today so will running individual wires to the lights . If this fixes the issues I will let you know ...

 

[sphelps]

Installed the new ground wires today . All the lights worked good and strong but the left running light . I got a faint flickering left side marker light and the same on the left rear side marker but no left running light ..
Everything else worked perfectly ... Could this problem be on the truck side ?.. I had the U-haul place wire the truck about a year ago ...