Wiring inside trailer ?????

I have a 25' boat trailer with the light ran inside the trailer beams. The old wiring needs to be replaced with new. When I try to pull it out with new wire attached, it keeps getting hung up. Is there a way to run new wiring through the beams by pushing some type of heavy wire through first?? How is this done at the factory and can it be replaced?? Any advice appreciated.

Re: Wiring inside trailer ?????

the only thing I can tell you is when you use your old wire as a pull wire I sometimes solder the ends and then wrap in electrical tape from the heel to the toe or from the new wire to the old wire so that the tape threads are on the back of the tape, sometimes you may need to twist the pull wire a little while giving slight pressure to pull, then simply cut the soldered section out and terminate the lights, the problem is that if you have to pull too hard you may skin the new wire and that is unacceptable so wireing outside of the beams may be in order.

Don't give it to much attention, if its not going to work then simply run the wire outside of the beam its just fine that way when properly protected and secured, a much better situation then a skinned wire inside of the beams.

Again slightly pull while twisting the old wire sometimes you may need to have someone on the other end spinning the new wire in order to get the wire to pull, gently pulling the wire back and forth while spinning it sometimes works too but again gently and you may need someone on either end, if you get it but can feel resistance be careful because that can be a sign that you are skinning the wire.

Re: Wiring inside trailer ?????

If you have a Harbor Freight near by get one of their fiberglass wire pull kits or a fish tape and use that instead of trying to push a piece of heavy wire through. Tie a loop of strong string to the end before you start feeding it in. Use the string to attach the new wire to.

3/16" x 33 Ft. Fiberglass Wire Running Kit
50 Ft. Fish Tape

The big hardware stores carry these also, they're just cheaper at HF.

Re: Wiring inside trailer ?????

To help run the wires use a old trick my Grandpa tought me. Take a plastic bag or balloon blow air into it making it just big enough to fit in the 1/2" hole. Tie a string on to it & stick it in the hole. Tape off the end your not going to use. Take a vaccum hose to the other end and suck the bag/balloon to you. You may have to rap a plastic bag around the vaccum hose and trailer, I used tape, to make an air tight seal. The tie the wire to the string & pull it to you.

Re: Wiring inside trailer ?????

I usually tie a piece of cord or wire to the old harness before pulling it out, that way I've got a means to pull the new wires back through the tubes. If you cut the old wire harness, you can simply use the old wires to pull the new harness through.
For new trailers, I have a few old lengths of fishing rod heat shrink wrapped together with the guides removed that I fish wires through with.

Re: Wiring inside trailer ?????

often what is hung up is a splice in the middle for the running lights. And speaking of which, that is a major failure point at the splice, so you are better off running a dedicated wire to the running light rather than splice mid-stream. Plus splicing and fishing it out of the hole is a pain.

I rewired one recently and couldn't get the old wires to serve to pull through the new (they broke midstream), and I didn't have an electrician's fishing wire, so I improvised by pushing a 25' tape measure through. Then you tape a string and reel it back; then you use the string to pull the wire. It worked great and I was right proud of figuring this out until disaster struck. See, I had the tape measure small end hooked over the end of the beam, and set the big end in the opening of the trailer beam. Well it came unlocked and my tape measure shot about 4' up into the trailer! Couldn't pull it through, couldn't push it back so I had to build a coathanger on a pole device to retrieve it!

So watch the spring-loaded device; learn from my error.

A plumber's snake would work, too. Also bungee-joined tent poles.