Troubleshooting Electric Trailer Brake Assembly Magnets
Question:
I have a two axle trailer with 12” electric brakes. I’m getting 8 amps out of the brake controller at 12 volts. I checked the resistance at the trailer plug blue and white wire. It was 2.4. I disconnect each magnet and tested for ohms. Each one came back 3.8-4.0, expect for one that was open. I replaced that magnet and retested at the trailer plug. The resistance went down to 1.6. I’ve been trying to find the answer to this one simple question, but no one seems to know it or even ask the question. Does the resistance go up or down when connecting multiple magnets? I would think the better the connection, the lower the resistance. But don’t know for sure.
asked by: Mike
Expert Reply:
We have an article to assist with checking your brake magnets like you are stating. The resistance will go down because the brake magnets are connected in parallel. Since the voltage doesn't change, the amperage draw needs to increase to power the magnets. This is Ohms law in action based on my research.
You obviously already have a multimeter like # PT89ZR so if you determine based on the article that you need to replace magnets, I recommend # BP01-180 for 12 inch Dexter assemblies or # AKBRKR-M12 for a more cost effective alternative.
Products Referenced in This Question
Replacement Magnet Kit for 12" Electric Trailer Brake Assemblies - 5,200 lbs to 7,000 lbs
- Accessories and Parts
- Trailer Brakes
- Electric Drum Brakes
- 5200 - 7000 lbs
- Brake Magnets
- 12 Inch
- etrailer
more information >
Replacement Trailer Brake Magnet for 12" Brake Assemblies
- Accessories and Parts
- Trailer Brakes
- Electric Drum Brakes
- Brake Magnets
- 12 x 2 Inch
- Redline
more information >
Digital Multimeter with 42" Long Test Leads - LED Display
- Electrical Tools
- Testers
- Multimeter
- Yellow
- Performance Tool
more information >
Product Page this Question was Asked From
Dexter Electric Trailer Brakes - 12" - Left/Right Hand Assemblies - 6,000 lbs
- Trailer Brakes
- Electric Drum Brakes
- Standard Grade
- Manual Adjust
- 12 x 2 Inch Drum
- 6000 lbs Axle
- 14-1/2 Inch Wheel
- 15 Inch Wheel
- 16 Inch Wheel
- Dexter
more information >
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