Trailer Light Grounding Problem

[shugga]

Hello. New member, first post. We recently boat a new (to us) boat and the right side trailer lights don't work. I'm not very mechanically or electrially inclined, but I believe the problem is that there is a .23 reading on the multimeter when I put it on the spot where the lights are supposed to ground. Is this caused by some sort of short somewhere?
Thanks in advance.
David

 

[Tinlizzy]

Re: Trailer Light Grounding Problem

Welcome to the forums!

Before getting into detail, did the lights work when you purchased the boat/trailer? And if so, seeing the right side has stopped working have you replaced the bulb?

Post your findings

 

[kenmyfam]

Re: Trailer Light Grounding Problem

Verify bulbs are O.K. then remake your ground connections. Your .23 reading means nothing to me as there is no mention of .23 what ????
Scrape away if necessary to make a really good ground. You would be amazed how many trailer light issues are ground related.
Welcome to iboats.

 

[PondTunes]

Re: Trailer Light Grounding Problem

Remove the light and try cleaning the bolt/ground wire terminal with a wire brush, you can clean the metal where the ground attaches in the same way, this should ensure you have a good ground. If it still doesn't work trailer lights are usually run from one bulb to the next, if you set your meter to DC voltage, and don't show 12 volts at the socket follow the wires back to the next socket you should find your problem pretty quick.

 

[Tinlizzy]

Re: Trailer Light Grounding Problem

As the above poster stated, on a lot of trailers the grounds are tied into the light brackets, wich tend to be steel of some sort/finish and rust heavily. What I usually do is remove the ground from the bracket and use a metal tech screw and fasten it to the frame.

 

[BrianS.]

Re: Trailer Light Grounding Problem

Run a ground wire to every light, you'll thank yourself later.

 

[redfury]

Re: Trailer Light Grounding Problem

Shared ground wires usually either leave you without lights, or one heckuva problem.

Depending on the lights on the trailer, usually the ground in the assembly is from the metal ground plate on the inside of the assembly to one of the wires ( brown ) going into it from the back. I've had lights where all the wire does is enter the back and is held by spring tension from the bulb being placed in the socket, or conversely, when the bulb is placed in the socket, it releases the tension on that wire causing a bad connection and thus no ground, equaling no light.

LED lights are the way to go with a fresh set of wires in the trailer. No accidentally burnt out bulbs from water hitting the bulbs when the brake light comes on blowing it, and no corrosion to deal with either. $75-80 for the lights and the wiring and you won't have to worry about it for a long long time.

 

[shugga]

Re: Trailer Light Grounding Problem

Verify bulbs are O.K. then remake your ground connections. Your .23 reading means nothing to me as there is no mention of .23 what ????
Scrape away if necessary to make a really good ground. You would be amazed how many trailer light issues are ground related.
Welcome to iboats.

Bulbs are good. Moved them from 1 side of the trailer to the other. Bulb worked on one side then not the other.
.23 is volts. On the other side of the trailer, there is no significant readings. Just to clarify, there is a terminal at the end of the ground that mounts to the bolt that bolts the light to the frame. The ground is supposed to be connected to this bolt. I can disconnect the ground from the bracket completely and then get a reading on the voltmeter at this bolt. Actually, I can get a reading from the whole bracket.
It seems to me like there has to be some other wire that is somehow touching the frame and is conducting electricity back to this bracket. And is causing there to be no ground.

If I take the ground and place it directly on another one of the bolts from the frame, instead of the light bracket, there are a couple of sparks and then the bulb lights up.

Does any of this make sense?

 

[shugga]

Re: Trailer Light Grounding Problem

As the above poster stated, on a lot of trailers the grounds are tied into the light brackets, wich tend to be steel of some sort/finish and rust heavily. What I usually do is remove the ground from the bracket and use a metal tech screw and fasten it to the frame.

Like I said, not very mechanically inclined , what is a metal tech screw?

 

[shugga]

Re: Trailer Light Grounding Problem

Remove the light and try cleaning the bolt/ground wire terminal with a wire brush, you can clean the metal where the ground attaches in the same way, this should ensure you have a good ground. If it still doesn't work trailer lights are usually run from one bulb to the next, if you set your meter to DC voltage, and don't show 12 volts at the socket follow the wires back to the next socket you should find your problem pretty quick.

I used some sand paper to clean the bracket, bolt, nut, and terminal. Can't say that they looked perfect, but they looked better than the working side

 

[shugga]

Re: Trailer Light Grounding Problem

Welcome to the forums!

Before getting into detail, did the lights work when you purchased the boat/trailer? And if so, seeing the right side has stopped working have you replaced the bulb?

Post your findings

Bought the boat yesterday from a dealer 2+ hours away from home. There was no tech there, but the salemen found the initial problem (main ground at the front of the trailer). The boat was a "broker", or we probably would have left it there for them to figure out. Actually, hindsight 20/20 we probably should have done that anyway.

 

[shugga]

Re: Trailer Light Grounding Problem

And thanks for all of the greetings!

 

[Tinlizzy]

Re: Trailer Light Grounding Problem

If you are grounding your black lead to the bracket and it completes the circuit (lights the bulb), then where you attached the black lead, attach the ground, and it will do the same for the light. Complete the circuit. (light the bulb)

I am trying to make this as simple as possible

These are tech screws:
http://www.tool-net.co.uk/p-311486/tool-net-4-2-x-13-wafer-head-bzp-philips-self-drilling-screw.html

I like using wafer heads, they have a large head for good contact. And a low profile.