Trailer ground

[rrlund]

Is it normal to need an extra ground wire between a pickup and trailer? I took the box off my pickup this week and put a flatbed on it. I had to disconnect the trailer plug wiring to get it out of the bumper, then hooked it back up and put it through a hole in the back of the flatbed. I tested it with a test light, hooked the clip of the test light to the neutral pin, touched the tip to each of the other pins and they all worked like they should.

I backed up in front of the gooseneck livestock trailer and plugged it in. None of the lights worked. I didn't want to crank it all the way down on the ball to see if grounding it that way would light them up, so I hooked the jumper cables to the truck hitch and the trailer. Everything lit up and worked. In all honesty, I never tried just plugging the trailer in without being hooked on when I still had the old box on the trailer, so I don't know if this is a new thing. Do I need to hook up ground wires with a plug so I can just ground it when I hook on, or do they all just ground through the ball? Why wouldn't the neutral pin in the plug do it?

 

[Jim.ME]

Is it normal to need an extra ground wire between a pickup and trailer? I took the box off my pickup this week and put a flatbed on it. I had to disconnect the trailer plug wiring to get it out of the bumper, then hooked it back up and put it through a hole in the back of the flatbed. I tested it with a test light, hooked the clip of the test light to the neutral pin, touched the tip to each of the other pins and they all worked like they should.

I backed up in front of the gooseneck livestock trailer and plugged it in. None of the lights worked. I didn't want to crank it all the way down on the ball to see if grounding it that way would light them up, so I hooked the jumper cables to the truck hitch and the trailer. Everything lit up and worked. In all honesty, I never tried just plugging the trailer in without being hooked on when I still had the old box on the trailer, so I don't know if this is a new thing. Do I need to hook up ground wires with a plug so I can just ground it when I hook on, or do they all just ground through the ball? Why wouldn't the neutral pin in the plug do it?

The socket and the plug are both supposed to have dedicated ground wires. So, yes you need to have a ground wire from the trailer plug to the trailer frame, the ball is not intended to be the ground.

If your trailer has brakes, the ground wire should be at least 12 gauge, some recommend 10 gauge.

What plug are you using, 7 wire flat blade some people call the RV type?

 

[rrlund]

I'm using the small round six pin that came stock in the bumper on the 07 Ford Super Duty. It's what was wired in the truck when I got it 11 years ago, so that's what I kept using. It was easier to just use that style plug on the trailer than mess around trying to change something in the truck.

 

[Jim.ME]

I'm using the small round six pin that came stock in the bumper on the 07 Ford Super Duty. It's what was wired in the truck when I got it 11 years ago, so that's what I kept using. It was easier to just use that style plug on the trailer than mess around trying to change something in the truck.

Here is a picture showing what is accepted standard wiring for that style plug.

 

[MarkB_MI]

It's best to have a separate ground, as you can't depend on the hitch and ball to provide a solid ground. LED lights don't really care, but with incandescent bulbs a bad ground can give you fits. Ever see a trailer where the marker lights flash in concert with the turn signals?

 

[Janicholson]

The socket and the plug are both supposed to have dedicated ground wires. So, yes you need to have a ground wire from the trailer plug to the trailer frame, the ball is not intended to be the ground.

If your trailer has brakes, the ground wire should be at least 12 gauge, some recommend 10 gauge.

What plug are you using, 7 wire flat blade some people call the RV type?

If you are calling the white wire the neutral, it is actually ground. If the plug on the truck was tested (as in your description) the ground is working there. the ground in the male connector on the trailer is likely the failure. The wire may be correctly connected in the plug, but failed corroded or internally broken where it attaches to the trailer frame. Jim

 

[Janicholson]

The socket and the plug are both supposed to have dedicated ground wires. So, yes you need to have a ground wire from the trailer plug to the trailer frame, the ball is not intended to be the ground.

If your trailer has brakes, the ground wire should be at least 12 gauge, some recommend 10 gauge.

What plug are you using, 7 wire flat blade some people call the RV type?

If you are calling the white wire the neutral, it is actually ground. If the plug on the truck was tested (as in your description) the ground is working there. the ground in the male connector on the trailer is likely the failure. The wire may be correctly connected in the plug, but failed corroded or internally broken where it attaches to the trailer frame. Jim

 

[Jim.ME]

If you are calling the white wire the neutral, it is actually ground. If the plug on the truck was tested (as in your description) the ground is working there. the ground in the male connector on the trailer is likely the failure. The wire may be correctly connected in the plug, but failed corroded or internally broken where it attaches to the trailer frame. Jim

Your reply was intended to be to rrlund's original post, wasn't it? I didn't mention a neutral.

 

[Janicholson]

If you are calling the white wire the neutral, it is actually ground. If the plug on the truck was tested (as in your description) the ground is working there. the ground in the male connector on the trailer is likely the failure. The wire may be correctly connected in the plug, but failed corroded or internally broken where it attaches to the trailer frame. Jim

yes, but the failed connection is still likely in the trailer. Jim

 

[Jim.ME]

yes, but the failed connection is still likely in the trailer. Jim

Agreed

 

[J.Wondergem]

Is it normal to need an extra ground wire between a pickup and trailer? I took the box off my pickup this week and put a flatbed on it. I had to disconnect the trailer plug wiring to get it out of the bumper, then hooked it back up and put it through a hole in the back of the flatbed. I tested it with a test light, hooked the clip of the test light to the neutral pin, touched the tip to each of the other pins and they all worked like they should.

I backed up in front of the gooseneck livestock trailer and plugged it in. None of the lights worked. I didn't want to crank it all the way down on the ball to see if grounding it that way would light them up, so I hooked the jumper cables to the truck hitch and the trailer. Everything lit up and worked. In all honesty, I never tried just plugging the trailer in without being hooked on when I still had the old box on the trailer, so I don't know if this is a new thing. Do I need to hook up ground wires with a plug so I can just ground it when I hook on, or do they all just ground through the ball? Why wouldn't the neutral pin in the plug do it?

I aways do run a ground wire thru the plug. I got in a habit of that on my semi tractors. Keeps the lights from blinking.

 

[Tony in SD]

I would not depend a ball hitch for a ground connection. Most of our work trailers have a pintle hitch. For certain I would not rely on a pintle hitch for a dependable ground.

 

[zuhnc]

In addition to the ground wire through the electrical connector, a ground wire to EACH light is a good idea. Don't depend on a possible corroded attachment bolt at each light to maintain a good connection. zuhnc

 

[old]

In addition to the ground wire through the electrical connector, a ground wire to EACH light is a good idea. Don't depend on a possible corroded attachment bolt at each light to maintain a good connection. zuhnc

Yes you can never have to many grounds

 

[john in la]

I run the ground wire all the way to the lights with waterproof connectors and do not use any part of the trailer frame as a ground especially on my boat trailer.
Aluminum trailers; electricity and salt water do not play well together.

 

[John T]

Good mornin RR, good question and as expected being electrical you got plenty of responses, lots of fine gents on here. FWIW having owned wired and messed with countless trailers over many years, here is my advice and response:

1) Even if it may work without it,,,,,,,,,,Even if not absolutely necessary,,,,,,,,,,,Even if the physical trailer ball to truck could provide an adequate ground current return path BASED ON YEARS OF EXPERIENCE, I STRONGLY ADVISE THE USE OF A DEDICATED GROUND WIRE FROM TRUCK BATTERY NEG BACK TO TRAILER USING THE ROUND 6 PIN PLUG/CONNECTOR if thats what you have and wish to use .

2) My typical practice was to run a dedicated ground wire (at least 12, 10 Gauge even better) from the truck battery back to the ground pin on the trucks receptacle. Its the truck battery NEG post which is the source even though sure that's also connected to the trucks iron frame..

3) Similar, I preferred use of a dedicated ground wire to each and every light instead of relying on the truck or trailers iron frame alone for the ground

4) When splicing trailer wiring I recommend using the correct devices I 1) Crimped,,,,,,,,,,2) Soldered,,,,,,,,,,,,,3) Heat Shring Tubing,,,,,,,,,,4) Coated with Liquid Tape

As always its YOUR trailer YOUR money and YOUR choice how to proceed, this is simply what experience has taught me to be the best

Best wishes

John T

 

[JOCCO]

Good mornin RR, good question and as expected being electrical you got plenty of responses, lots of fine gents on here. FWIW having owned wired and messed with countless trailers over many years, here is my advice and response:

1) Even if it may work without it,,,,,,,,,,Even if not absolutely necessary,,,,,,,,,,,Even if the physical trailer ball to truck could provide an adequate ground current return path BASED ON YEARS OF EXPERIENCE, I STRONGLY ADVISE THE USE OF A DEDICATED GROUND WIRE FROM TRUCK BATTERY NEG BACK TO TRAILER USING THE ROUND 6 PIN PLUG/CONNECTOR if thats what you have and wish to use .

2) My typical practice was to run a dedicated ground wire (at least 12, 10 Gauge even better) from the truck battery back to the ground pin on the trucks receptacle. Its the truck battery NEG post which is the source even though sure that's also connected to the trucks iron frame..

3) Similar, I preferred use of a dedicated ground wire to each and every light instead of relying on the truck or trailers iron frame alone for the ground

4) When splicing trailer wiring I recommend using the correct devices I 1) Crimped,,,,,,,,,,2) Soldered,,,,,,,,,,,,,3) Heat Shring Tubing,,,,,,,,,,4) Coated with Liquid Tape

As always its YOUR trailer YOUR money and YOUR choice how to proceed, this is simply what experience has taught me to be the best

Best wishes

John T

What are you talking about John !! You sound like me!! Crimped and soldered, just use those little squeeze me together plastic connectors.

 

[JOCCO]

RR they have all given good advice on the ground situation and I am in the camp of most of them and John T Bad ground is probably close to the top of 12v wire issues. I've seen many times what the guy said about lights flicker or intermittent. good luck

 

[John T]

RR they have all given good advice on the ground situation and I am in the camp of most of them and John T Bad ground is probably close to the top of 12v wire issues. I've seen many times what the guy said about lights flicker or intermittent. good luck

Bad ground is probably close to the top of 12v wire issues.

Ditto XT Exactly Been there done that lol

John T

 

[John T]

What are you talking about John !! You sound like me!! Crimped and soldered, just use those little squeeze me together plastic connectors.

Just pinch together Scotch Locks,,,,,,,,, No wire stripping, No crimping, No soldering, what could possibly ever go wrong in a trailer with all the water sand and rust LOL

John T