Came up on a cargo trailer, little help here with wiring.

[mjeds]

a bit wordy, as I wanted to provide some background. issue at the bottom.

so I came up on a free 2009 Forest Wind Tail Wind 12x6 cargo trailer, neighbor of a friend brought it to CA from TX, apparently in TX cargo trailers under 4K lbs used on farms are not required to be registered, as such this trailer was never registered or titled, so once in CA the DMV would not register it without the TX DMV paperwork, original bill of sale, or the manufacturer statement of origin.

This gentleman got 2 tickets for using it on public streets without tags, the second one was several hundred dollars, so he just wanted to get rid of it.

doing a bit of research with the CA DMV I discovered that a notarized bill of sale from a private party sale could be used to register and title the trailer, so I had my attorney create one, the gentleman signed it as selling the trailer to me for $1.00 and we got it notarized, done deal $36 later the trailer is titled and registered.

EXCEPT:

I also need to have a CHP inspection of the trailer and the lights do not work. So I have a temp operating permit for 30 days to fix this,.

I got under the trailer and discovered that the wiring is a mess, something must've chewed through it at some point as it is wire nutted (not even crimped) in several spots, and not wired correctly (i.e. to a standard 4-pin color pin out). right turn applies brake lights, left turn flashes right signal, brake flashed left, no tail lights at all.

so I ripped everything out, my truck has a 7 pin connector and I'm not a fan of 4-pin anyway, plus I think I want to add e-brakes to this trailer at some point, so I bought a full 7-pin harness on Amazon and re-wired everything and replaced all the 14 year old incandescent lights (marker, tail, turn, etc) with LEDs.

everything is working great except one thing. the 7-pin has a 12volt line for battery charging, I installed a motorcycle sealed AGM battery to power the interior lights of the trailer and a roof vent fan.

But I am not getting 12volts on that line. only 3volts.

Checking at my truck and I get a full 12 volts, checking at the junction box I get a full 12 volts, checking at the battery and I only get 3,

same harness and hookup for my travel trailer, and full 12 at the battery,

any ideas?

 

[Rollin Ollen]

a bit wordy, as I wanted to provide some background. issue at the bottom.

so I came up on a free 2009 Forest Wind Tail Wind 12x6 cargo trailer, neighbor of a friend brought it to CA from TX, apparently in TX cargo trailers under 4K lbs used on farms are not required to be registered, as such this trailer was never registered or titled, so once in CA the DMV would not register it without the TX DMV paperwork, original bill of sale, or the manufacturer statement of origin.

This gentleman got 2 tickets for using it on public streets without tags, the second one was several hundred dollars, so he just wanted to get rid of it.

doing a bit of research with the CA DMV I discovered that a notarized bill of sale from a private party sale could be used to register and title the trailer, so I had my attorney create one, the gentleman signed it as selling the trailer to me for $1.00 and we got it notarized, done deal $36 later the trailer is titled and registered.

EXCEPT:

I also need to have a CHP inspection of the trailer and the lights do not work. So I have a temp operating permit for 30 days to fix this,.

I got under the trailer and discovered that the wiring is a mess, something must've chewed through it at some point as it is wire nutted (not even crimped) in several spots, and not wired correctly (i.e. to a standard 4-pin color pin out). right turn applies brake lights, left turn flashes right signal, brake flashed left, no tail lights at all.

so I ripped everything out, my truck has a 7 pin connector and I'm not a fan of 4-pin anyway, plus I think I want to add e-brakes to this trailer at some point, so I bought a full 7-pin harness on Amazon and re-wired everything and replaced all the 14 year old incandescent lights (marker, tail, turn, etc) with LEDs.

everything is working great except one thing. the 7-pin has a 12volt line for battery charging, I installed a motorcycle sealed AGM battery to power the interior lights of the trailer and a roof vent fan.

But I am not getting 12volts on that line. only 3volts.

Checking at my truck and I get a full 12 volts, checking at the junction box I get a full 12 volts, checking at the battery and I only get 3,

same harness and hookup for my travel trailer, and full 12 at the battery,

any ideas?

Check that you are using the correct ground. It sounds like you might be getting a partial ground by using one of the circuits that are wired to a circuit that is not being energized.

Darrell

 

[GTS225]

I agree with Darrell. The ground you're using as a test point may not be grounding worth a hoot with your tow vehicle, which is your primary voltage supply. Hitch balls are typically a bad ground to use for that. Wire that battery negative to the ground in your 7-pin, as well as trailer frame.

Roger

 

[Kevin D Pem]

I will add to above great advice!!
The white wire you connected to the frame of trailer gives an alternative ground to the ball coupling, but!!! The box is not guaranteed to have a good ground to the frame. What we are all saying is we think you didn't make a ground circuit for your secondary system.

 

[mjeds]

I bought a 7-pin solid state cable with its own j-box:

Amazon.com.

installed the j-box inside the trailer at the rear door behind the lip, which is covered by an aluminum panel.

grounds are solid.

so decided to try a separate power cable directly from the truck to the battery and I get a full 12 volts,

so, it appears this prewired cable I bought on Amazon must have a break somewhere inside, I contacted the seller and explained the situation and got no reply but 2 hours later I had a full refund and notification of a shipment arriving tomorrow with a replacement cable, so I am guessing this is not the first time they have had an issue with their cable. No response, automatic replacement and refund?

if there is a break inside, I don't want to risk an electrical fire, so I pulled it out, and will try the replacement when it arrives tomorrow.

 

[mjeds]

so definitely their harness, connected the new one up to the truck to test it and the power line has a full 12v, appears to be only with ignition on, probably a Hyundai thing as I recall my previous Avalanche and Silverado's both were hot all the time.

but the keyed 12v line doesn't bother me, rather not have the trailer kill the SUV battery.

now i have to phish the damn line under the trailer again, ugh.

 

[mjeds]

ok, took a few days, but.

new wiring,
added ramps to the drop door and to cover the door gap.
added e-brakes
replaced all the lights
added a cargo box
added e-tracks and motorcycle chock
new tires and wheels
had it painted with rhino liner


putting some decals on it later this week to give it some definition. ~~~~~~~~~~~~~~~


before:

After:

 

[TheLooks]

Very nice!