Brake rewiring

[crocke]

Hello all,
First post in a long time. I have had fifth wheels since 98. I had a Coachman then but now have a 36RLTS by Jayco of course. I have a problem with the brakes not working as well as I want them to. I pull with a 2008 F350 single rear wheel. I have taken the trailer and truck in to the respective shops, Ford dealer and General trailer. Both say that everything seems fine. I did this after a panic stop that left us both very unnerved.
I have decided that the wiring upgrade will give me the braking that I am seeking. I understand the wiring diagram that are out there, the star diagram and heavier wire, 10 gage or heavier. The question I have is how far back do you take the heavier wire? If you are only taking it from the new junction box won't there be a current drop between the plug on the trailer side to the junction box. Or am I missing something? It seems to me that the heavier wire should at least go to the plug. Can anyone clarify this for me? Thanks in advance,

Bob C

[Happy Jack]

Bob, before buying a bunch of wire I would check all connections on both the trailer and truck.
The 7 pin plug on your truck is exposed to weather, connections tend to get corroded. How does the cable on the trailer look, has it been run over? I had a trailer that the 7 pin plug had been replaced and the screw connections had worked loose.
What type of brake controller do you have?
I upgraded my brake controller to a Tekonsha P3 but even my old controller could lock the trailer brakes if I set the adjustment too high.
Here's a site that tells you how to check your trailer brake magnets. http://www.etrailer.com/faq-testing-...-function.aspx
If you end up replacing the wiring, you can use this guide to calculate the size of wire needed. http://www.offroaders.com/tech/12-vo...gauge-amps.htm
You would calculate the length from the brake controller to the farthest brake magnets on the trailer...

[steveb285rks]

You could run 10 gauge from the brakes to the junction box. As for the pigtail, you will have to determine what size brake wire is in there. It's probably 12 gauge. From there you need to determine the size of the wire from the brake control to the plug. According to e-trailer the max amp draw is 15-16 amps. Here is a link and it has their 10 ga 2 wire shielded by the ft. http://www.etrailer.com/question-12234.html

Have you ruled out brake adjustment, shorted wiring in the axle tubes and shorted magnets?

[crocke]

Thanks for the responses. I haven't checked the wire size yet. I blew out my knee a couple weeks ago and found the link from 09 about the brake rewire. As I said both the Ford dealer and the trailer dealer checked out and of course charged for their services. I have been dealing with the Ford dealer for over 20 years so I trust them maybe a mistake but they have been straight with me. As far as the brake controller it is the stock Ford controller,integrated and I run it at 8-8.5 at all times. I seem to remember that they only spoke of volts and not amp's.
I have been doing brakes for most of my life both professionally and personally as a mechanic at a big ten college here in Michigan. So you have given me some things to check besides the rest. If any more idea's come to mind please let me know.............Bob

[Spike99]

.

For all my utility, boat and RV trailers, I purposely remove their linear "inside axle tube" wiring and replace with 10 gauge STAR design "outside the axle tube" wiring design. New 10 gauge wiring from trailer tongue's 7-pin connector, to junction box, to each wheel hub. All connections are soldered as well. Before and after design upgrade comparison is amazing. Not only better and more consistent braking power, but much higher level of safety as well. IMO, STAR design should be minimum factory build. Perhaps in time....

As a suggestion, don't waste one's time over analyze factory's default linear using 12 gauge wire against much better STAR design using 10 gauge wire. Simply upgrade to much better STAR design and enjoy.

re:
http://i178.photobucket.com/albums/w...ing-Linear.jpg
http://i178.photobucket.com/albums/w...iring-Star.jpg
http://i178.photobucket.com/albums/w...g/100_1433.jpg
Note: Safety support chain is optional on trailer. I installed safety support chain under my utility trailer because it gets dragged through all sort of bush and garbage land. For my boat and RV trailers, I didn't use the safety chain. But, did install wires inside the plastic wire loom - like shown in above picture.

As implied, don't waste time analyzing before and after. Simply "do the upgrade" and enjoy one's benefits afterwards. STAR design is that much better.