True Ground?

[scrit9mm]

Re: True Ground?

You mean connect the negative terminal of the battery to negative terminal of the harness and positive leads to the plug terminals for the various lights right?

No, I am attempting to establish a ground, something that I know is grounded. That's where the battery came in. I was unsure if the negative of a battery that was not installed in a car was a ground. I wanted to ensure that in fact my ground on my trailer was working or not by testing it on a absolute ground (instead of scraping metal from a frame somewhere and touching the ground wire to it). The wiring harness on the trailer is connected to the plug on my vehicle.

I suppose the metal screw that came with the trailer kit is not a sheet metal screw, or the area that I drilled through to attach the screw is not "clean" enough to create a ground.

 

[UncleWillie]

Re: True Ground?

No, I am attempting to establish a ground, something that I know is grounded. That's where the battery came in. I was unsure if the negative of a battery that was not installed in a car was a ground. I wanted to ensure that in fact my ground on my trailer was working or not by testing it on a absolute ground (instead of scraping metal from a frame somewhere and touching the ground wire to it). The wiring harness on the trailer is connected to the plug on my vehicle.

I suppose the metal screw that came with the trailer kit is not a sheet metal screw, or the area that I drilled through to attach the screw is not "clean" enough to create a ground.

That is what I was worried about.

It is all relative.
There are NO ABSOLUTES here!
A ground is a concept, not a real physical item.
You can not buy a "ground" and walk around with it in your hand.
But, you can form a ground between two or more object.

The ground terminal on the battery is simply that, the ground of the battery. Nothing more.
When you connect the ground terminal of the battery to the frame of the vehicle then the two of them are grounded together.
This would now be considered your ground.
But this is now to be considered the ground of your vehicle. And nothing more.

At the risk of being redundant, I am going to say it again, it is all relative.
There are no absolute grounds.
You, personally, decide what you're going to call ground, and work from there.

------
The wire you have screwed to the frame will probably work just fine today.
It's not a matter of being "clean enough", it's a matter of overdoing it the first time, and not having to do it again.
This is a situation where "well enough" is really not "good enough".
So, unless you go the extra mile, you're going to have the same problem in the future, and d?j? vu will set in.

 

[etracer68]

Re: True Ground?

Some light kits are grounded through the mounting studs on the back of the light. If they are not tight to the steel on the trailer they will not work right.

 

[smokeonthewater]

Re: True Ground?

Unclewillie is telling you right but I fear that you don't understand how electricity 'works' and as such you may be missing his point


picture electricity as a liquid and the battery as a pump..... Imagine that the electricity wants to flow from the positive terminal of the battery to the negative..... you CAN use a separate battery for testing but you have to use the positive and negative from only that one battery. Electricity will not 'flow' from the positive of the battery in your vehicle to the negative of another battery of to a grond stake driven into the earth or anywhere else except back to the negative on the battery in the vehicle.

Soooo the path here is through the wiring in the vehicle, through the trailer plug to the trailer wiring, to the lights, to the trailer frame, back through the light plug to the vehicle frame, and through the negative battery cable back to the battery.

You ABSOLUTELY have a ground (negative connection) issue between the trailer and vehicle..... do NOT assume that it has to be on the trailer side.....

 

[jeeperman]

Re: True Ground?

The kit is a sealed unit. there is only 5 wires coming from the harness.

White> ground

Brown> Left
Yellow

Brown> Right
Green

Your connector could be faulty.
with a test light, Do you get power when you test between the white wire at the ring lug to a hot wire?

 

[scrit9mm]

Re: True Ground?

thanks uncle willie and smoke, you affirmed my question.

as for etracer, is there a way to decide if my kit is one that requires the grounding of each light other than trial and error?

Jeeperman, I have not tested this with my meter but it does work with my other trailer and I am not going to change my set up on my vehicle to accomodiate this trailer which I will only haul 5-6 times a year.

 

[bruceb58]

Re: True Ground?

No, I am attempting to establish a ground, something that I know is grounded. That's where the battery came in. I was unsure if the negative of a battery that was not installed in a car was a ground.

OK, I can see you are confused. The negative post on a battery is not a ground. It is the negative post on the battery and that's all it is. It could be connected to a ground but it is not ground.

Do my test where you hook up a battery jumper cable between your car frame and the trailer frame. If the lights start working, you have just isolated your problem to the ground going through the vehicle/trailer harness/plug. If that doesn't solve your problem, your ground issue is at the lights. This test splits your problem in half. Right now, you don't know where the bad ground is.

 

[UncleWillie]

Re: True Ground?

Smoke,
Thanks for the graphical explanation.
It's nearly impossible to introduce electrical theory in two paragraphs.
But we are masochists, and we just enjoy trying.

You ABSOLUTELY have a ground (negative connection) issue between the trailer and vehicle..... do NOT assume that it has to be on the trailer side.....

Earlier, he said...

What makes me believe that this is a grounding wire issue at the trailer is that everything works properly on my other trailer.

So we might, and I say might!, just make the assumption that it is the trailer.

9MM,
Just remember that whatever electricity comes out of the battery has to be returned to the Same battery.
The circuit will be...

battery positive > wiring > lamp > ground circuit/wiring > back to the battery negative.

-------------
So much for the theory let's get something practical going.

Do you have a volt meter to use for testing or anything that can be used for testing?
You will need some kind of test equipment to figure this out, or you will drive yourself crazy.

Your other option is just to dismount each lamp assembly and clean the connections under each one. And then put them back on.
Without any test equipment, this is just going to be a shotgun afair.
It is not efficient, but it will work.

 

[UncleWillie]

Re: True Ground?

Duplicate Post.

Is there any way to delete this?

 

[bruceb58]

Re: True Ground?

If your tail light assemblies have only 2 wires, there are no seperate grounds required to hook up.

 

[UncleWillie]

Re: True Ground?

thanks uncle willie and smoke, you affirmed my question.

... is there a way to decide if my kit is one that requires the grounding of each light other than trial and error?

Your Welcome.

Stick with it. As painfull as it seem, we will get you through this.

There is no question about it, the grounding of each light is required.
This is how the power gets back to the Battery.

 

[Texasmark]

Re: True Ground?

I have never seen an OEM trailer that is missing the ground wire.

Bruce my man, problems are after the OEM is finished with it and it has been in the field for who knows how many years with who knows for owners. BTDT

 

[Texasmark]

Re: True Ground?

If your tail light assemblies have only 2 wires, there are no seperate grounds required to hook up.

Yes Bruce; one is the low current running light (brown) wire and the other is the pulsed high current directional signal (green or yellow, depending upon which light is blinking) and the return is via the mounting hardware/trailer frame to the white wire attached to the trailer frame via the trailer/tow vehicle interconnect to the tow vehicle frame to which the battery - is attached and alla, you have conduction.

Did I miss anything?

Mark

 

[Texasmark]

Re: True Ground?

OK, I can see you are confused. The negative post on a battery is not a ground. It is the negative post on the battery and that's all it is. It could be connected to a ground but it is not ground.

Do my test where you hook up a battery jumper cable between your car frame and the trailer frame. If the lights start working, you have just isolated your problem to the ground going through the vehicle/trailer harness/plug. If that doesn't solve your problem, your ground issue is at the lights. This test splits your problem in half. Right now, you don't know where the bad ground is.

Bruce, the Battery is the EMF that powers everything. You know that. Ground is nothing more than something used as a common reference that is opposed to the potential....you know that.

Since a battery is the vehicle (as opposed to land power systems...houses, industry..etc.) EMF for lights, the +12v terminal is the positive lead (power source) and the - terminal is the negative lead (power return to complete the current path). For convenience it is tied to the vehicles chassis and to any towed item via the frame ground (white wire) grounding (you know that). The wiring from the + 12v terminal goes through fuses to protect wiring from melt downs in the event of short circuits....you know that.

The word Ground came about in power line terminology in that ground was the earth that we stand on and hence made a nice reference for the low side of a voltage circuit...putting a 5/8" 8' copper rod into it and attaching to you powerline usage confirms it.

On vehicles you don't have the earth but power comes from the battery......soooooo the battery - terminal is connected to the chassis of the vehicle which becomes the "earth ground" for all practical purposes for the vehicle. Since the vehicle's power comes from the battery and the battery has a + and -, the - becomes the "earth ground" if you will.

What did I miss????

Mark

 

[oregoncruiser]

Re: True Ground?

This seems to be taking a somewhat simple process and turning it into rocket science. In the amoutn of time spent typing and reading, you could easily ground each light and the trailer. Don't mean to sound disrespectful, just want to help you get the thing grounded and move on to a funner project.

Try the jumper cables from bare metal on the trailer to bare metal on the tow vehicle. This will tell you if the ground problem is in the plug connection. If it is, you need to confirm that your tow vehicle has a dedicated ground. Many do not. If it does not, you need to create one by attaching a ground wire to the frame of the vehicle, and running it to an available terminal in the vehicle plug. On the trailer side you need to tie into that terminal and do one of two things. Run that wire to each invidual light, and attach it to the metal mounting frame of the light. Or you can clean/grind a section of the trailer frame near the hitch and attach the new ground wire to the frame here. Attaching the ground wire to the frame, should ground the trailer, but might/might not ground each light.

If the jumper cable trick does not work, the problem will be that the individual light is not making great contact. In this case, remove the light, clean/scrape/wirebrush both surfaces and re-attach. If this doesn't work, you will probably need to run a dedicated ground wire from the plug(Trailer side) clear back to each individual light. I've had to do this on trailers that have been used in salt water.

Keep in mind it is also possible to encounter both problems, bad ground connection between tow vehicle and trailer, AND bad ground connection between trailer frame and light bracket. Best off to "overdo it" once as stated above. I'd strongly suggest you start at the tow vehicle and work your way back to the lights, installing dedicated grounds, and cleaning/scraping/wirebrushing each contact point.

After I achieve success, I coat each ground connection with something to seal the connection. Even painting over the connection will help slow down future corrosion.

Hope this helps, and doesn't add to the confusion. If I was a bit closer (Or Vs. AL) I'd come help you. Grounding issues are fairly easy to correct, but often very difficult to diagnose.

 

[scoyt]

Re: True Ground?

Anytime I rewire a trailer, I use the same wire they use for a extension cord. I go to the hardware store and get a spool of black 14 gauge wire. Then I run the wires to the lights themselves. Put the 2 wires that are supposed to go to the light as the should go. Then put the green wire to the back of the light, for a ground. Then hook the green wire to the white wire. Just my $.02

 

[Texasmark]

Re: True Ground?

That is what I was worried about.

It is all relative.
There are NO ABSOLUTES here!
A ground is a concept, not a real physical item.
You can not buy a "ground" and walk around with it in your hand.
But, you can form a ground between two or more object.

The ground terminal on the battery is simply that, the ground of the battery. Nothing more.
When you connect the ground terminal of the battery to the frame of the vehicle then the two of them are grounded together.
This would now be considered your ground.
But this is now to be considered the ground of your vehicle. And nothing more.

At the risk of being redundant, I am going to say it again, it is all relative.
There are no absolute grounds.
You, personally, decide what you're going to call ground, and work from there.

------
The wire you have screwed to the frame will probably work just fine today.
It's not a matter of being "clean enough", it's a matter of overdoing it the first time, and not having to do it again.
This is a situation where "well enough" is really not "good enough".
So, unless you go the extra mile, you're going to have the same problem in the future, and d?j? vu will set in.

I follow you and somewhat agree on a "true ground" for a mobile vehicle, but ground is nothing more than the negative side of a power source. Since the battery is the power source in most mobile vehicles and it develops it's potential power (energy till dissipated as power..ala current flow) via a - and + terminal, then the - terminal by definition becomes the "earth"...for the environment....ground and the + term the hot or source of electrons....course it is the source for the absence of electrons....holes....where electrons vacated...electrons came from the ground....valence ring of atoms that have an abundance of loosely held electrons which move about freely when acted upon by an electrifying force...Physics 101.

Mark

 

[bruceb58]

Re: True Ground?

I follow you and somewhat agree on a "true ground" for a mobile vehicle, but ground is nothing more than the negative side of a power source.

This is way off the original topic but Ground can be connected to the positive side of a source as well. Like I said before, ground has nothing to do with the positive or negative terminals of a power source. For example, if you had a circuit such as an amplifier that required plus and minus voltages, the supply powering the minus voltage would have its postive leads connected to ground.

Way back when there were positive ground voltage systems in some cars. Ground is just relative to other voltages and that's it.

back to the topic on hand...don't run seperate grounds to each light as one poster suggested. That creates more of a nightmare later. KISS...keep it simple stupid...also means no seperate grounds.

 

[Silver Eagle]

Re: True Ground?

Try running a wire from your trailer to your tow vehicle.If you have a wire on your plug as a spare wire use that. I had to do that on my last trailer.Go from bolt to bolt. Not to the battery.

 

[H20Rat]

Re: True Ground?

Bruce my man, problems are after the OEM is finished with it and it has been in the field for who knows how many years with who knows for owners. BTDT

I bought a different snowmobile trailer about a month ago that came like this. Looked like factory wiring, zero splices, all original lights. The 4 wire connector wasn't 4 wires, it had no white wire coming out of it. It wasn't cut off either, the connector was molded with only 3. It relied on a hitch ground, which worked marginally well at best. Might have it in the garage yet, i'll have to snap a pic.