Originally Posted by mfMcFroggierPod
Brakes seem weak and are not wearing.
Tandem axle 4 wheels
Inspected annually/ No grease noted on brake shoe/ or magnet surface.
What gauge wire is routed to your brakes?
I get 2.69A / wheel at brake application, what is normal?
It sounds like you only have one magnet working. According to Dexter each magnet draws around 3 amps and you then multiply that by the number of brake assemblies, in your case four.
A common cause of this problem is the connectors where the main brake wire is attached to the individual wires from the brake magnets.
I would check current at each brake backing plate with a clamp type ammeter with controller gain set to max and manually applied.
Another cause of poor braking if all else is working properly is glazed brake shoes. While drums are off just use a sanding block with some medium/coarse sandpaper to remove the glaze. Sand along the shoe lining, not across it which can leave flat spots. Glazing can occur when frequent and light braking is done on tow vehicle and gain is set low on controller. Once brake pedal is touched, brakes on trailer are activated but not enough to do much more than glaze the linings. Turn up gain and avoid unnecessary application of brakes. Coast to a slower speed when possible rather than using brakes.