Trailer brake behavior

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Intelliduner
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Trailer brake behavior

Post by Intelliduner »

Gang,
I was trying to figure out why a brake/turn light wasn't working on my trailer, and at one point I had a couple wires hooked up to a loose battery and was testing the various pins on the wiring connector to see what lit up. I found the pin for the brakes, and heard a small click from the axle. I tried it again just for curiosity sake, and it didn't click any more. Again, nothing. Is it normal for trailer brakes to not return on their own? Or could I have mucked something up that caused them to freeze or something to fry?

It's a new trailer, and I haven't used the brakes yet (I still need a controller), so I have no idea if they're working as they should or not.

thanks!
_d

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Post by quad1100 »

The brakes should only work when power is applied to them. If you were to disconnect the power to the trailer the brakes should disengage. Now on some trailers there is a safety disconnect which applies power to the brakes continues. It is a small plunger with a cable attached to it, the cable gets secured to the tow vehicle and if the trailer becomes detached during tow it will pull the plunger. This might be one reason your brakes are not disengaging; the plunger might not be put in properly?

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Intelliduner
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Post by Intelliduner »

quad1100 wrote:Now on some trailers there is a safety disconnect which applies power to the brakes continues. It is a small plunger with a cable attached to it, the cable gets secured to the tow vehicle and if the trailer becomes detached during tow it will pull the plunger. This might be one reason your brakes are not disengaging; the plunger might not be put in properly?
I don't have a breakaway on this trailer (I don't even have brake controllers in my tow vehicles yet), so that shouldn't be a problem. It's almost like I blew a fuse in it, but AFAIK, there are no fuses in the trailer wiring itself. I would think the fuse would be part of the controller's wiring.

_dennis

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Post by Sandemon »

What you are probably hearing is the magnet attatching itself to the brake drum, it will not make any noise when it is relesed. A quick expaination of the workings of electric trailer brakes is, an elctro magnet is mounted to an arm that has a cam on the top, when you put electricity to the magnet it grabs the face of the drumand is pulled by the turning drum ,the cam on the top of the arm pushes the brake shoes out against the drum giving you brakes. This explanation is far from complete but gives an idea as to how your trailer brakes work :twisted: 8) :)
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Intelliduner
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Post by Intelliduner »

Sandemon wrote:What you are probably hearing is the magnet attatching itself to the brake drum, it will not make any noise when it is relesed.
Ok, but shouldn't it make the same noise again when the power is applied again? I would think it would click each time, but it sounds as if the magnet stuck the first time and stayed there. I guess I'll know if the wheels drag when I try to move it :P

_dennis

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Post by Fuzzy Knight »

Dennis
It may not make the same noise again as it may have not moved far from the drum surface. It only has a small air gap and once the power was removed from it it could still be on the surface of the drum.
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Post by ejunior2 »

The first time you applied current to it the magnet in the brakes probaly has some space between and you probably just heard the magnet hitting the drum. When you disconnected the power there may be now reason for the magent to back away from the drum so re-applying current won't make a sound.

Just a thought.
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Post by Intelliduner »

That makes sense--thanks, guys :D

_dennis

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