Testing the Amperage Draw of Trailer Brake Magnets

Updated 07/13/2012 | Published 07/12/2012

Products Featured in This Question

Electric Trailer Brake Assembly - 10" - Left Hand - 3,500 lbs

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$52.66

Digital Multimeter with 42" Long Test Leads - LED Display

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$23.83

Question:

I have all my brakes removed from my 5th wheel trailer and am ready to install all new brake assemblys. All I have at each axle is the wiring for the new magnets to be installed to, can I check for any amp at these wires before I hook up the magnets.

asked by: Garry

Expert Reply:

You can check for amperage but depending on the size of the magnets they will draw a certain amount no matter what the amperage is on the wire. I have included a link to an FAQ article that should help you. You will want to look at the section titled Testing Individual Brake Magnets.

10 and 12 inch brake assembly magnets should show 3.2 to 4.0 amps max at 12 to 13 volts per magnet. 7 inch brake assembly magnets should show 3.0 to 3.2 max amps at 12 to 13 volts per magnet. You can use a multimeter like # PT89ZR if needed.

expert reply by: Michael H