Low boy Trailer re-wiring

I finally have got enough time to look at my trailer and tried to find out why electricals were [mostly] not working. I did some standard
troubleshooting tricks and found out that I have a bad ground connection. When I cleaned up an area of the trailer with an angle grinder and hooked up a 12v negative to that, instead of white on the plug, the lights lit up.
This trailer uses the body of the trailer as a negative ground. I have a feeling that it does not work well after rust sets in.
I would like to ask if it makes sence to just redo it all, rip out and throw everything away, and make new wiring.
Since I have forklifts, I can easily turn the trailer to the side or upside down.
i
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Ignoramus15400 wrote:

Just like 99% of trailers out there.

That would be the best way. Use a standard trailer color code and run power/ground to ALL lights.
Run the wiring in conduit and on the front end install a sealed junction box. In it connect all the grounds to one point. All the markers to another, turn signals and such go to their own spots. When you do this I would suggest adding back-up lights. Charging circuit for on-board battery. Plus any other items you might want later.

--
Steve W.

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On Sun, 01 Jan 2012 19:09:36 -0600, Ignoramus15400

It was built like a damned Brit car, eh? That sucks. ;/

Absolutely. It'll take you 1-3 hours and cost under $50, unless you already have some UV-rated extension cabling. Does it have a channel or box frame? Feed it through a box frame or clip it to channel. Run separate grounds, then ground through the connector. I prefer 7-wire.

Sure! You could flip it up and lean it securely and safely, just like this guy did to weld his gas tank: http://goo.gl/4Bxoe ( NOT! )
-- Win first, Fight later.
--martial principle of the Samurai
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OK, what kind of cable should I use, to avoid deterioration over the years in Illinois weather.
i
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On 1/1/2012 9:18 PM, Ignoramus15400 wrote:

Normal trailer wiring harness - inside PCV pipe.
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I am sorry, but what do you mean by "normal trailer wiring harness"? I thought that I would need to do all wiring connections from individual wires?
i
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On 1/1/2012 10:34 PM, Ignoramus15400 wrote:

Trailer wiring harnesses are available off the shelf in many connector types and wire lengths. 16 ga for light circuits but heavier for other uses... 12 for brakes - hmmm - I missed that one.
All details at: http://www.etrailer.com/faq-wiring.aspx
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On Sun, 01 Jan 2012 22:34:45 -0600, Ignoramus15400

I've always used jacketed cable and only pulled out wires for the terminations. I'd slit the jacket, expose the ground/backup wires, solder leads onto them, and then tape well.
Get a holder for your black tape. It makes it much easier to wrap cable. I've made 20' harnesses this way, too. It takes great patience.
When I was looking for a holder to refer you to, this image came up and caught my eye. It might be best to keep it in your office at the warehouse, not at home. <wink> http://goo.gl/VLjGo It's for Japanese Scotch tape, I think.
This is more like the holder I have: http://goo.gl/b8Lyw The circular depression wraps around the wires while you wrap. It keeps the tape tighter than winding by hand, and helps prevent wrinkles, keeping the harness drier.
Another tip: If you ever loan out the trailer or use other people's vehicles to tow it, install a 4-wire cable end in addition to the 7 and keep a couple extra vehicle ends so you can quickly hook up if you need to. They're a couple bucks each, plus scotchblocks. http://goo.gl/Sahwi
-- Win first, Fight later.
--martial principle of the Samurai
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On Mon, 02 Jan 2012 06:42:17 -0800, Larry Jaques

No way will I lend my big flat deck trailer to anyone except my sons. If asked, I question if the would-be borrower has (1) electric brakes (2) a 14 pin double row flat socket on the car. That kills the "loan" every time. No problem lending my worn out 7 x 4 box trailer, it has a standard 7 pin plug. All our vehicles have standard round 6 & 7 pin sockets + the 14 pin.
    Alan

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Ignoramus15400 wrote:

Use common trailer harness wiring and you can redo it in another 3 years.
Use GOOD wire inside conduit and run separate grounds and feeds for each light. Seal the connections and use good components, use LED lights and you won't need to touch it for over 20 years unless you crash it.
Make it so that you can replace the plug and the stinger cable on the vehicle end, that way when you forget to unhook it OR a hitch fails you can just replace the stinger without tearing out the rest of the harness.
Use a common trailer harness clipped to the frame and you can replace it in 3-4 years just like you are now. Also make sure you use a coupler end that has enough connections for all the points you have including ground. That may take a 6 pin or a 7 pin.
--
Steve W.

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On Sun, 01 Jan 2012 21:18:21 -0600, Ignoramus15400

Why, the -good- stuff, of course. <groan> Look for "trailer cable". http://www.awcwire.com/ProductSpec.aspx?id=Trailer-Cable etc.
http://www.etrailer.com/faq-wiring.aspx Handy reference.
-- Win first, Fight later.
--martial principle of the Samurai
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As you're certainly not the first to do this, what you need is a replacement, sealed, modular wiring harness.
Unless you need/want to invest in the tools, connectors, etc gary

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It may be easier to weld heavy copper wire ground leads directly to the steel frame. You already have the equipment to do this.
Joe Gwinn
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On 1/1/2012 7:09 PM, Ignoramus15400 wrote:

...
Virtually all trailers and truck bodies were...
Unless the wiring is in bad shape otherwise I don't see much sense in spending time doing more than cleaning up the ground(s); surely you have more productive use of your time than doing something just for the heck of it???
I'm presuming this probably was a (very) used and perhaps unused trailer for quite some time so nobody did anything for years. One pass through and it should be good to go for quite a long time yet (again, unless the wiring itself really is badly weathered which I'd guess isn't the case).
BTW, the other place to check is the lamp sockets/bases and connections. They've probably had some leakage over the years and if the dielectric grease is gone that's a good corrosion point as well. Clean them and the bulb bases up well and recoat w/ grease.
I've one old ('58) grain truck; the bed lights on it are still functional. Have done the ground connection and the sockets a couple of times in that time; it's not a frequent need is what I'm getting at.
--
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I have a special copper-filled conductive grease, which, I hope, will make a difference.
i
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This sounds like ordinary anti-seize paste. The standard anti-oxidation paste (used on aluminum wire connections) is zinc dust in silicon grease.
But welding or soldering a piece of copper or brass to the steel frame will make for a permanent fix.
Joe Gwinn
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I've had good results from tapping a hole and installing a stainless steel (vehicles) or brass (antennas) grounding screw dipped in LPS3. On the antennas which don't see road salt Ox-Gard paste lasts for years. I've mixed brass, steel, stainless and aluminum without corrosion problems up there.
jsw
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