Electrc Brakes Intermittent Problem

Yes they should have there own Earth from the battery in 6mm wire.

Also re wire your boat trailer the Earth wire is the first wire to wick! go green, then black, and turn to dust! so that could also be the problem.

Cheers.

Had a similar problem a few years back. Replaced all the wiring still couldn'tfix it. Turned out it was a faulty wire going into the brake magnet

TerraFirma

I have installed the Prodigy in 4 vehicles and used the dedicated earth wire from the unit back to the battery on three of them and via the body on the other.

All work perfectly, however I must stipulate that the aforementioned earth via the body/chassis is on a Toyota Troopy that has a zillion 12V Modifications on it which earth through the body or chassis.

To do this successfully you have to run a number of large diameter/gauge earth straps from the Drive train to the Battery & chassis, chassis to the body and then body to the battery.

I use nothing less than 25mm/sq for this purpose.

Also, I only use a minimum of 6mm cable (not squared) for the following ie power from battery(Black), earth (white), Pwr to rear 7 pin socket(blue) & 4mm for the red brake activation/switching cable

That covers the vehicle.

The Trailer/etc/

I use minimum 6mm (not squared) cable which will fit into a 7 pin large round plug/socket from the plug to the brakes and back again ensuring that you balance/split each wheel or side of vehicle being towed evenly.

To do this I usually make the split/divide/splice approx 1m from the plug and then run the pwr and earth to the brakes down each of the chassis rails using 6mm cable. These cables are used only for the brakes, the lights, indicators etc run in their own 7 coloured 4mm multi cored cable.

Every bodies mind is in turmoil at this point because they are thinking - this idiot has gone from 6mm on the vehicle to 4mm multi core on the trailer to 6mm on the trailer brakes.

Not so. I just bi-pass the blue & black 4mm cables in that 1st metre of the trailer cable with the above mentioned 6mm Blue & Black electric brake cables.

The 6mm earth becomes the common earth cable for the trailer.

Now the main problem areas are as follows:

Joints of electric brake wires to the trailer cable wires - usually about 250mm from brakes themselves. For whatever reason these suckers either may come apart, corrode or lose conductivity

The plug & socket - These also suffer degradation from water, dirt/mud, stress and strain from heavy handed operators who pull, push and in general just abuse them so that that wires come out of sockets or pins lose their conductivity etc etc.

In May this year in Alice Springs I offered to rewire a plug into an old caravan for a guy and after two hours of intermittent faults I ended up cutting the new plastic large 7 pin Hella plug that he gave me to use off, and replaced it with a new 7 pin round aluminum Narva plug.

Everything then worked perfectly. I have used both Hella and Narva for many years without any problems and it just so happened that the Narva product was the only available replacement.

So! don't make the assumption that the plug and corresponding socket are perfect.

Never did identify what was the problem with that plug.

Last possible problem in the setup may be the the automatic circuit breaker that you should by law have used between the battery and the prodigy unit.

Hope this helps you

DD