Problem with trailer brakes

[petendoll]

Today I hooked up to my trailer. I checked to see that my brakes were working. Nothing.
I pulled the emergency pin to see it that operated them. Nothinig. I don't believe my problem is from the truck to the trailer plug. I have a new battery in the trailer that should have activated the brakes when the emergency pin was pulled.. Where do I start my search for the problem? Bad ground?

[joebedford]

I've been trying to add this to the existing thread for the last three days but have been unable to. Does the forum block posts to 'old' threads? The thread had fallen off the top 4 pages. It doesn't matter... I just realized that there was a percent sign in my message - that's the 'reason' it wouldn't post.

Continuing on trying to make my brakes work and correcting problems:

I tried the compass method today. DW was pressing the brake pedal on the truck - 2 seconds on 2 seconds off - while I moved the compass around. I tried it on the wheel side and the backplate side - I couldn't get any reaction. Wonder what I was doing wrong. Suggestions?

I decided to do the ear test - the front 4 wheels hummed but the back two didn't.

Turns out when I did the repair I mentioned earlier in 'this' thread, I didn't hook up the rear axle properly.

Now I'll have 50 percent more braking power. I hope I'll be able to take the pedal gain adjustment off 10.

[Dr_Quick]

My question is how are you testing the brakes? Electric brakes will not work unless the wheel is turning. The magnet tries to grab the inside face of the drum, the lever causes the shoes to expand and stop the trailer.
To test mine, I jack up one wheel and have someone energize the brake control while I spin the wheel.

[Gdetrailer]

..

[petendoll]

Charlie D. wrote:
Careful pulling the emergency pin. I have read that doing so while hooked up to truck can burn it up.

Thank you for that bit of knowledge.

[Chris_Bryant]

FWIW, most smart phones have magnetometers in them along with compass apps.

[Charlie_D_]

Careful pulling the emergency pin. I have read that doing so while hooked up to truck can burn it up.

[joebedford]

On my way to Texas in December, I lost my trailer brakes. Futzed around with the truck quite a bit but ultimately it was cut wires at the axles. I must have run over something. I had to repair THREE connections.

I'm pretty sure my rig DOESN'T have a fuse in the brake circuit.

[chiefward]

Had this same problem a couple of weeks back and the problem turned out to be a bad ground from battery to frame.

[petendoll]

Thanks for the in put. I'm going out this morning to see if I can trace it down. I know this sounds stupid, but I never thought of checking the fuse on the trailer. STFS still makes lots of sense. I have no power to any wheel so a fuse is probably top of the list. For some reason I always tend to think major before minor. Thanks again. I will post what I find.

[Lynnmor]

fitznj wrote:


The other way is to put your ear near each wheel, if the brake is working you will hear a humming sound and if you touch the wheel you may feel a vibration.

If he pulls the break-away switch and sends DC current to the magnets, what would cause a hum? A controller might supply a pulsating current, but a battery would not.

[Hondavalk]

Yup - great idea BUT...... have you tried finding a magnetic compass these days? I tried several major stores last year with no luck.
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Any sporting goods store will have lots of compass's ranging from 3.00 to 35.00 dollars. :B

[brulaz]

BB_TX wrote:
Battery disconnect switch actuated?

Don't think there should be any other disconnect switch in the line feeding the brake-away switch. Only a fuse.

Are all the brakes gone or just one?
In my case, the problem was a broken wire at the drum.
But that only affected a single wheel.

I would pull the disconnect and start tracing the wiring back from the wheels, looking for voltage.

[fitznj]

Hold a compass down close to trailer brake drum ----lower area.....then have someone pull pin on emergency brake switch.

Does compass needle deflect towards drum
NO....then magnet is not being energized so wiring needs to be checked
YES...then magnet is being energized and brakes need adujstment

Yup - great idea BUT...... have you tried finding a magnetic compass these days? I tried several major stores last year with no luck.

The other way is to put your ear near each wheel, if the brake is working you will hear a humming sound and if you touch the wheel you may feel a vibration.

[pawpaw47]

Old-Biscuit wrote:
Hold a compass down close to trailer brake drum ----lower area.....then have someone pull pin on emergency brake switch.

Does compass needle deflect towards drum
NO....then magnet is not being energized so wiring needs to be checked
YES...then magnet is being energized and brakes need adujstment

Great idea! Never thought about doing that.