Trailer lights, bad ground?

[Tri-Motorhead]

Ok need a trailer light guru if we have one. I have towed my 2003 Scamp since 2003 and have had zero issues with Three different trucks. With the cybertruck not so good. If headlights are on, my trailer marker lights turn off and I have no break lights. If I turn off head lights, turn and break lights work.

could it be bad ground on truck? Or is my trailer old enough that I now need to “ground” the negative 12v to my trailer?

other trucks- 1999 Ram, 2004 Ram, 2008 Toyota Fj.

any help appreciated!

thanks

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[mongo]

Ok need a trailer light guru if we have one. I have towed my 2003 Scamp since 2003 and have had zero issues with Three different trucks. With the cybertruck not so good. If headlights are on, my trailer marker lights turn off and I have no break lights. If I turn off head lights, turn and break lights work.

could it be bad ground on truck? Or is my trailer old enough that I now need to “ground” the negative 12v to my trailer?

other trucks- 1999 Ram, 2004 Ram, 2008 Toyota Fj.

any help appreciated!

thanks

Is the truck going into trailer mode?
Are your trailer lights LED or incandescent?
4 pin or 7 pin connector?
The trailer's harness should have a frame grounding wire (versus relying on ball/hitch contact).

 

[Tri-Motorhead]

Is the truck going into trailer mode?
Are your trailer lights LED or incandescent?
4 pin or 7 pin connector?
The trailer's harness should have a frame grounding wire (versus relying on ball/hitch contact).

Thanks for the reply Mongo,

Truck does go into trailer mode blue, while in park. Put CT in drive trailer mode goes into red.
this is a 7 pin system. Trailer converted to LED lights.

I have read in some trailer forums that this in becoming common as older trailers like mine are a through wire system and new trucks are more wired for the trailer ground.

guess I’ll need to go splice mount and test a trailer ground.

 

[Woodrick]

Ok need a trailer light guru if we have one. I have towed my 2003 Scamp since 2003 and have had zero issues with Three different trucks. With the cybertruck not so good. If headlights are on, my trailer marker lights turn off and I have no break lights. If I turn off head lights, turn and break lights work.

could it be bad ground on truck? Or is my trailer old enough that I now need to “ground” the negative 12v to my trailer?

other trucks- 1999 Ram, 2004 Ram, 2008 Toyota Fj.

any help appreciated!

thanks

Not really looking at anything but your trailer age, odds are that the trailer wiring has an issue. While it may work with other vehicles, still look to verify the trailer wiring.

Grounds are notorious with trailers. Oxidation is a problem.

It is a common practice to go through every bulb, every socket and clean then out and clean the contacts (disconnected from the vehicles and local batteries disconnected) find every spot where there's a wire connected to the frame, remove it, clean it, replace and spray with something to protect it.

It's an extremely common issue with trailers a lot younger than yours.

If it doesn't fix the problem, trust me, it was needed.

 

[Tri-Motorhead]

Not really looking at anything but your trailer age, odds are that the trailer wiring has an issue. While it may work with other vehicles, still look to verify the trailer wiring.

Grounds are notorious with trailers. Oxidation is a problem.

It is a common practice to go through every bulb, every socket and clean then out and clean the contacts (disconnected from the vehicles and local batteries disconnected) find every spot where there's a wire connected to the frame, remove it, clean it, replace and spray with something to protect it.

It's an extremely common issue with trailers a lot younger than yours.

If it doesn't fix the problem, trust me, it was needed.

Thanks Woodrick,

Trailer is a 2003 Scamp and the negative 12 volt wire doesn't get grounded to the frame on this trailer, which I believe is the problem with the pairing the Cybertruck and probably any newer truck. Tail lights converted to LED earlier this and still work fine on my Toyota FJ which I still have in the driveway.

The truck side 7 pin on the FJ and all vehicles before were "ground" to the truck. I believe I am going to have to splice and ground to the trailer with the new configuration.

I just haven't had anyone be able to confirm and say, yes that is what you need to do.

 

[mongo]

Thanks Woodrick,

Trailer is a 2003 Scamp and the negative 12 volt wire doesn't get grounded to the frame on this trailer, which I believe is the problem with the pairing the Cybertruck and probably any newer truck. Tail lights converted to LED earlier this and still work fine on my Toyota FJ which I still have in the driveway.

The truck side 7 pin on the FJ and all vehicles before were "ground" to the truck. I believe I am going to have to splice and ground to the trailer with the new configuration.

I just haven't had anyone be able to confirm and say, yes that is what you need to do.

I just confirmed the trailer harness ground from the Cybertruck is connected to truck chassis.
You may be experiencing a new vehicle issue where the paint is not yet rubbed off the receiver so there is no ground path through the hitch.

 

[Tri-Motorhead]

I just confirmed the trailer harness ground from the Cybertruck is connected to truck chassis.
You may be experiencing a new vehicle issue where the paint is not yet rubbed off the receiver so there is no ground path through the hitch.

ahhhhh good thought. It is some tick as paint. I'll go scrub the hitch receiver and hitch real good before I go cut any wires.

Thanks a ton!

 

[mongo]

ahhhhh good thought. It is some tick as paint. I'll go scrub the hitch receiver and hitch real good before I go cut any wires.

Thanks a ton!

Yeah, pointy meter probe took some force to make contact.

A ground on the trailer side is the best option though.

 

[Tri-Motorhead]

Did some paint sanding...Trying to work my full time job so I may not of done well enough. Currently no change. Wondering if the ground is loose on truck end, will climb under and investigate when I can.

Thanks for the help

 

[mongo]

Did some paint sanding...Trying to work my full time job so I may not of done well enough. Currently no change. Wondering if the ground is loose on truck end, will climb under and investigate when I can.

Thanks for the help

Do you have a meter or 12V test light?
Module ground is a chassis ground so if it works at all, it's grounded.

 

[Woodrick]

Thanks Woodrick,

Trailer is a 2003 Scamp and the negative 12 volt wire doesn't get grounded to the frame on this trailer, which I believe is the problem with the pairing the Cybertruck and probably any newer truck. Tail lights converted to LED earlier this and still work fine on my Toyota FJ which I still have in the driveway.

The truck side 7 pin on the FJ and all vehicles before were "ground" to the truck. I believe I am going to have to splice and ground to the trailer with the new configuration.

I just haven't had anyone be able to confirm and say, yes that is what you need to do.

The ground to the frame shouldn't matter from the Cybertruck, as it's coming from the connector. You want to check the breakout point on the trailer where the wires split and go to their appropriate locations.

And also get a plug tester, so that you can plug it into the Cybertruck and verify what it is putting out.

Did the LEDS that you get have ballast resistors in them? That could be impacting something.

You can always just test things with a 12V battery hook up from ground to each of the circuits on the trailer.

 

[Woodrick]

I just confirmed the trailer harness ground from the Cybertruck is connected to truck chassis.
You may be experiencing a new vehicle issue where the paint is not yet rubbed off the receiver so there is no ground path through the hitch.

NEVER depend on the hitch as a ground! It moves, therefore guaranteed to be intermittent.

Trailers ground to the frames, just as vehicles do, because it is often a solid low resistance path and can save wire and keep ground potentials the same.

But hitches should never be looked at as conductors.

 

[mongo]

NEVER depend on the hitch as a ground! It moves, therefore guaranteed to be intermittent.

Trailers ground to the frames, just as vehicles do, because it is often a solid low resistance path and can save wire and keep ground potentials the same.

But hitches should never be looked at as conductors.

Yeah, I know...

The trailer's harness should have a frame grounding wire (versus relying on ball/hitch contact).

A ground on the trailer side is the best option though.

Their setup doesn't have that though:

Trailer is a 2003 Scamp and the negative 12 volt wire doesn't get grounded to the frame on this trailer, which I believe is the problem with the pairing the Cybertruck and probably any newer truck.

 

[Tri-Motorhead]

Well...I put the white neutral to the frame and no change. I have noticed that I get the Cybertruck Blue trailer Icon if I put the truck in reverse. In drive it is red.

Beginning to wonder if a couple wires are swapped at the pin connector on truck.

Yes the Scamp is what they call a through wire system and doesn't come with a ground to the frame. All the whites go where they are supposed to go.

Trailer light test works as far as I can tell, all lights flash etc.

I'm going to do some more research.

Thanks again for any and all comments as I figure out an old trailer and Space Ship.

This truck is freakin awesome otherwise.

Oh and my utility trailer with 4 pin flat, works just fine.

 

[Woodrick]

Well...I put the white neutral to the frame and no change. I have noticed that I get the Cybertruck Blue trailer Icon if I put the truck in reverse. In drive it is red.

Beginning to wonder if a couple wires are swapped at the pin connector on truck.

Yes the Scamp is what they call a through wire system and doesn't come with a ground to the frame. All the whites go where they are supposed to go.

Trailer light test works as far as I can tell, all lights flash etc.

I'm going to do some more research.

Thanks again for any and all comments as I figure out an old trailer and Space Ship.

This truck is freakin awesome otherwise.

Oh and my utility trailer with 4 pin flat, works just fine.

I think that the red light is telling you that it is unhappy.
I believe that you have electric trailer brakes. Any idea if they are working?

When you mention that the light test works fine, are they following the correct flashing sequence. You may want to hook the 4 pin trailer up and right down what lights have what flashing frequency and confirm that it is the same on the Scamp. Running lights, backup lights, brake lights and the turn signals all blink at different rates. I don't have them documented.

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