Trailer Brakes Hum But Do Not Engage

Question

Question:

I have replaced the trailer 7 pin connector. The truck is a 2012 silverado that has a 7 pin connecter. The trailer uses only 5 WIRES . All the lights work fine but the brakes hum but do not apply. brake lining checked , all good and adjusted. Ran a ground wire from ground side of the magnets to frame. Same result. have power coming to magnets from new controller. i have the ground wire from the magnets going to the ground connecter of the truck Just bought the trailer and believe it was not used for long time. When the magnets had a full 12 volts applied they locked up at that time i was trying to figure out the wiring. Thanks for your help. Does the wiring sound right. The wiring for the magnets is coming from the electric brake terminal of the truck. Thanks again.

asked by: Ray B

0

Expert Reply:

First, put the magnet ground wires nearby the magnets on the trailer frame. Running them far away makes it harder for the system to complete the circuit. You mentioned that power is getting to the magnets but how much power? TO determine that you can use a multimeter, # PT89ZR. If the brake controller is sending back the full power (turn up the gain as far as it will go) but only minimal voltage is getting to the magnets, the brakes are not going to work properly.

Using the multimeter you can determine where the power is being lost. You can check it in several places starting with the blue wire at the back of the brake controller. Then test the power output at the truck side trailer connector, then just behind the trailer side connector. And last check it just before the magnet.

There will be some voltage loss due to resistance from the wiring. But if you are only getting a couple of volts at the magnet or anywhere else, something else is going on. Make sure that your trailer side connector is pinned out to match the truck connector.

If you are using an adapter to go from the truck connector to the trailer connector then there could be something wrong with it and a new one would be the way to go.

It does not sound like the magnets themselves are the issue since they locked up at 12 volts. Somewhere between the controller and the magnets there is a power loss. Make sure that the truck and trailer connectors are clean and free of corrosion inside and out. I have included a link to our trailer wiring FAQ that will also help.

expert reply by: Michael H

0

Answer 1

There are a number of reasons why the brakes on your trailer may not be working. Lets start with the easiest things to check. First, check the vehicle and trailer connectors for corrosion. This can cause a short inside the connector and the brake…

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Answer 2

For your application you need the Easy Grease Trailer Hub and Drum Assembly for 3.5K Axles #AKHD-545-35-EZ-K to replace the Tru-Ryde RVD-H-545 trailer hub/drum assembly. This is designed for the industry standard #84 spindle so it uses inner bearing…

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Answer 3

Yes, the Dexter axle part #8327816 that you referenced has the exact same spindle as a Lippert 5,200 lb axle so the hubs and bearings would interchange.

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Answer 4

I recommend the Kodiak Synthetic Bearing Oil for Oil Bath Hubs - 8 oz Bottle #XLPROLUBE. It is a 90 weight synthetic oil. Dexter bought out Kodiak so this meets their specifications. I've also attached a photo of Dexter's recommended Oil…

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Answer 5

Dexter recommends a SAE 90, SAE 80W-90 or SAE 75W-90 oil to be used. I recommend the Kodiak Synthetic Bearing Oil for Oil Bath Hubs #XLPROLUBE as it is a synthetic 90 weight oil that helps reduce friction and to keep bearings cool. Since your cap was…

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Answer 6

You are correct, you should only be getting output when the brake is applied, or the override switch is activated. It sounds like the controller might be bad, but to make sure, you should probably bench test it before tossing it. Use a circuit…

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Answer 7

In order to determine the torque rating for the lug nuts on your trailer you will need to know check out the chart I attached that shows all of the torque specs for all the trailer lugs available based on stud size, wheel material and wheel size.

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Answer 8

There are a couple of things that may cause what you are stating. If you have checked the power draw with a multimeter like #PT89ZR and see the brake power isn't fully disengaging, then I recommend cleaning the ground connection to the magnet and…

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Answer 9

To replace the master cylinder on your Titan 10 brake actuator you can check out the diagram of the actuator I have attached. In the diagram there are two bolts that are noted you need to loosen to get to the master cylinder. They are part number 20…

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Answer 10

It sounds like you're looking for the torque specs for the lug nuts on a 6,000 pound axle. For a hub with 1/2 inch studs, 90 to 95 foot-pounds is standard.

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Answer 11

To wire your electric brakes you will want to run 10 gauge wire #10-1-1 to one of the brakes and run it to the other brake, using butt connectors like #05732-2 to connect them. The grounds will not be spliced, each brake assembly should have its own…

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Answer 12

Thanks for the purchase and if your Electric Trailer Brake Kit w/ Dust Shields #AKEBRK-12 are not giving you full braking, even with the brake controller all the way up, you likely have a wiring issue as that is the root cause of most trailer brakes…

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