Explaining Low Voltage at Brake Assembly on Triple Axle Trailer

Question:

Hello, I hope someone can educate me on these magnet brake Assemblies. Max Output voltage of RAM truck OEM brake controller is 12v. When we replace brakes on a trailer, and have all brake assemblies disconnected, we have exactly 12v on brake wires, so no voltage all the way to axles of a trailer. When I connect the first magnet to a trailer brake wiring, voltage on assembly connection s to 8v. When I connect all 6 brake assemblies, I have 5v on all assemblies’ connections. Basically 12v becomes 5v when all magnets are connected. The is pretty significant and it makes the brakes very weak. We tested it on old worn assemblies, new assemblies, dexter assemblies- they all do exactly same thing, voltage to 5v when we have all six brakes installed. Is there any way to avoid that voltage ? Is that related to a magnet quality/materials it’s made with? Is there any converter exists that could increase voltage back to normal? Thank you very much in advance.

asked by: Tony

Expert Reply:

The more brakes you have the less voltage is available for each part. Since you have 6 brake assemblies you are going to have lower voltage no matter what you do. One thing you can do to help is make sure you are using adequate wire for the brakes. You want to at least have 10 gauge wire like the # 10-1-1. This will help as the power travels the length of the trailer and to the different brake assemblies. I would also make sure that each brake assembly has its own ground to help as well.

expert reply by: Robin H