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page 38
T-12-UT
Maintenance
Finding a system short is a matter of isolation. If the high amperage reading drops
to zero by unplugging the trailer, the short is in the trailer. If the amperage reading
remains high with all the brake magnets disconnected, the short is in the trailer wiring.
All electrical troubleshooting procedures should start at the controller. Most com-
plaints regarding brake harshness or malfunction are traceable to improperly adjusted
or non-functioning controllers. See your controller manufacturers data for proper ad-
justment and testing procedures. If the voltage and amperage is not satisfactory, pro-
ceed to the connector and then to the individual magnets to isolate the problem source.
12 volts output at the controller should equate to 10.5 volts minimum at each magnet.
Nominal system amperage at 12 volts with the magnets at normal operating tempera-
ture, i.e. not cold, system resister at zero and controller at maximum gain should be 3.0
amps for each magnet in the circuit.
