Brake Controller - Short

[mnichols]

Hello,

The other day I had some truck problems so a friend had to tow my trailer while my truck was being towed. He has a prodigy brake controller that would show a short and then it would go out. It did this a few time in the 30 minutes he towed my trailer. I then borrowed another friends truck (2013 Dodge with built in controller) to get my trailer home and I had the same issues. The mesaage on the dash would say the trailer was connected then it would show the short and not be connected. Now I have a 2008 Duramax with built in controller and I never seem to have this issue where it shows a short, but there are times when it feels like my trailer brakes aren't working as they should.

Since I just got the trailer home yesterday I haven't had a chance to search yet. Where should I start my search... back by the trailer brakes to see if I lost a ground or maybe a cut wire or check the box where all the trailer wiring connectes to the 7 pin plug wire? I also noticed that running lights etc work fine when connected to my truck but when I turned them on the 2013 Dodge the trailer had no lights, however the brakes did work when it showed the trailer connected. Thanks

[Gdetrailer]

You have a short back at the axles.

Several possibilities here.

The stupid designers of the axles decided it would be a wise idea to run the brake wiring THROUGH the axle tubing.

Bad idea to say the least, the wiring moves about inside the tubing and eventually ends up chaffing the insulation to the point of intermittent shorts like you are getting.

Since you are going to need to run new wire from side to side on each axle it would be a great time to REPLACE ALL the brake wiring. DO NOT run the wire through the tubes! Instead use wire ties to hold the wires on top or on the sides of the tubes or run the wire along the underside of the trailer and drop it at each axle (allow some slack for axle movement).

The manufacturers tend to use the lightest (and cheapest) wiring allowed which typically is 14Ga. While 14Ga can support the current it has a lot of resistance which robs you of a lot of braking power.

I ran two pairs of 10Ga from the tongue to the axles and boy the brakes I have is nothing short of incredible.

Second is in one or more of the backing plates the insulation on the wires managed to get in the way of the mechanical parts and is chaffed.

At the same time make sure you use weather proof splices, RV manufacturers use the cheapest (and fastest) method possible which is Scotch locks or plain crimp splices.

Both are common issues although it seams like the wire in tubing issue is a bit more common..

Do not ground the magnets at the back of the trailer via the frame, the ground wire NEEDS to be run from the tongue to the magnets per Dexter manual..

[enblethen]

I would start with the connector on the trailer. It could have water and corrosion on the wire terminations. Get some electrical grease before starting. Clean the conductors apply a liberal amount of electrical grease and reconnect.