re-wiring trailer brakes

[JRS]

The previous owner of my race car trailer installed multiple Scotch-loc taps in the brake wiring of my race car trailer. Since I have time to do it correctly and the trailer is about 15 years old, I'm going to change all the brake wiring from the front of the trailer to the brakes. Unfortunately, the previous owner also spliced in various gauges of wiring. The trailer is 32 foot long enclosed car hauler, with four brakes. From what I can tell from the web, I think 12 gauge multi-stranded will carry the proper amount of amperage for the length I need. Or should I use 10 gauge?

 

[Grizzly]

I believe 12 gauge is ample, maybe even overkill. 14 gauge ought to work as well.

 

[CKelley1]

a good rule of thumb is 14 gauge one axel, 12 gauge two axels, 10 gauge three axels while you are at it change the trailer lights to led's and you will drop your lighting load by 80%

 

[JRS]

Thanks for the wiring guidelines. I replaced the brake lights on the rear of the trailer with led's, but can't justify the cost to change out all the rest (clearance) on a 15 year old trailer. The rest of the trailer wiring doesn't appear to have the scotch taps.

 

[steved]

Removing the scotch-locs was the biggest single improvement in braking I did to my 5vr.

 

[jelag]

We use non insulated butt connectors to make all our connections than we found a shrink tube that has a heat set adhesive inside the tube... as it shrinks the adhesive melts and when it cools its a water proof connection... we use a clear tube and we've got some stuff that is 12-14 years old... I was under one of those trailers this week checking the 12 v battery that runs the accessories and the connections are still clean inside the tube which tells me they are still sealed water tight...

I had my 05 at the dealer with a problem 14-16 months ago and he was doing a wiring change from a wire that has chaffed on the back of the truck(fuel pump)... we were on the road at the time I wasn't ready to do this in the pouring rain... . as he was getting ready to make the connection I looked at his shrink tube... he started to explain what it was and I asked why he didn't use the style with the adhesive in it... since this connection was under the truck. . he said he'd never heard of it... .

I went out to the 5er and got him a piece a ft. long and asked him to use mine... . the wall thickness on my product was at least 50% thicker and of course the service manager was looking to see what we were talking about... the service manage had not seen it either. . he said an approved connection was with standard shrink tube. . as if that will keep the water and road treatment out in the winter...

Hope this helps... BTW I think the 12 gauge wire is more than ample as the brake circuit has a 20 amp breaker...

We do run an 8 gauge wire from the battery/alternator to the trailer connector and a good ground, than put the same 8 gauge wire in the male plug into the battery box on our work trailers. . we've found this really helps keep the trailer batteries up on a hot day when the charge voltage is cut back by the ECM...

 

[JMetzger]

jeleg,where do you find the shrink tubing with adhesive on the inside. I could sure use some of that.

 

[Nigel]

You can also find heat shrink butt connectors. You crimp as usual and then heat shrink and you can see the sealer ooze out the end. I get them at a local truck parts place but I would think you should be able to find them at your local NAPA or Autozone.



Nigel

 

[steved]

I am one not to trust crimped connections, just a personal opinion. I solder all my connections.

I have a catalog from DC Electronics (?) that sells all that kind of stuff. Heat shrink is available in different wall thicknesses and with/without adhesives.

 

[jelag]

Nigel, steved..... I use Del City - Wiring Products and Professional Electrical Supplies

I've found the butt connectors with shrink tube, and this sight has it... but they don't have a long enough tail to suit me... I like a tail on the shrink tube that goes back a ways. . I often cut a 2" piece for a joint...

I usually spend $200 to $300 a year with this company getting a variety of items... I usually buy bulk packages of items...

What I do like is the butt connectors for 2 x 3 wires... 2 wires in one side at one ID and 3 wires in the other side at another ID... great for the 5er and other big connectors...

steved, on your crimped connections, your right... it always bothered me... but with these butt connectors and no plastic to crush than the adhesive holds the whole thing together, we can make a field repair with a hand full of tools and a small butane torch and no electricity... . I used to be just like you, solder only but after all these years I've changed my personal thoughts. .

One of these days I'll get a photo of my battery box on the 5er which I tore apart and changed...

 

[JRS]

Your local Fastenal sells heat shrink tubing with adhesive in it.



As I started pulling out the old wire, I found all kinds of splices that were hidden by tape/split loom. Brakes work much better now.

 

[steved]

Nigel, steved..... I use Del City - Wiring Products and Professional Electrical Supplies

I'm glad someone can remember all this stuff... this is the place I deal with as well, and the triple wall heat shrink tubing is nice stuff.

 

[steved]

As I started pulling out the old wire, I found all kinds of splices that were hidden by tape/split loom. Brakes work much better now.

That's what I found as well... there were at least 12 scotch-locs in my brake wiring.

 

[Gary - K7GLD]

I'm like Steve - prefer soldered connections if at all possible - but I too also use shrink tubing, but didn't know the inner coating stuff was available - will check with NAPA next time I visit - thanks for the tip!

 

[BDaugherty]

I use the adhesive heat shrink as well as heat shrink but connectors. The heat shrink butt connectors are easier to use, but not as effective. One tip is to make sure that your crimp tool does not penetrate the insulation if you are using the butt connectors. It won't matter how much glue is in the connector if it is pierced right where the crimp is.



I second the practice of running a heavier constant power and ground wire to the 7 way plugs. In my application, I already had #0 hot and ground wires run from the left battery to a quick connector at the rear of the truck for my multi mount winch. I just stripped 1/2" of insulation and spliced and soldered a #10 weather shielded fuse holder to the hot wire. Then I ran #10 wire to the OEM 7 way and to the one I put in the bed. The ground wire works the same way, but without the inline fuse holder.

Another tip is to run a separate ground wire from the battery to the trailer to prevent overloading the factory ground wires running from the battery to the body/frame.

 

[steved]

One thing to add... Del City also carries the wire for electric brakes, the double stranded wire within a insulation.