got voltage but no brakes

Maybe the wire going to the magnet is broken? An OHM reading would verify.

check the ground wire connection. Might have to pull the hub off and check for broken wire at magnet

Look here testing magnets

Is voltage 8.6 at other wheel(s)as well,and is/are it/they fully engaging? If yes and yes,it's time to pull the brake mag and check it and connections.
My knee jerk is that a wire or connection was damaged during the blow-out. Did any tread peel away and flop around?
A few tests.
Unplug 7 way cord and pull the break-away device (make certain house battery is charged and online:W) to see if brakes engage. If yes the problem is outside the brake assembly on wheel and wireing to front of trailer so look from front of trailer going toward TV and controller. Reset break-away to prevent discharging house battery. If no,test as below.
There should be no resistance between chassis of tow vehicle and trailer frame to begain.
If brake mags are grounded to frame,there should be no resistance from mag - wire to frame.
If mags are grounded by continus wire from TV,should be no resistance at connections.
That should get you started. If this doesn't find the culprit,we will go to + side and controller next.

da.bees wrote:
Is voltage 8.6 at other wheel(s)as well,and is/are it/they fully engaging? If yes and yes,it's time to pull the brake mag and check it and connections.
My knee jerk is that a wire or connection was damaged during the blow-out. Did any tread peel away and flop around?
A few tests.
Unplug 7 way cord and pull the break-away device (make certain house battery is charged and online:W) to see if brakes engage. If yes the problem is outside the brake assembly on wheel and wireing to front of trailer so look from front of trailer going toward TV and controller. Reset break-away to prevent discharging house battery. If no,test as below.
There should be no resistance between chassis of tow vehicle and trailer frame to begain.
If brake mags are grounded to frame,there should be no resistance from mag - wire to frame.
If mags are grounded by continus wire from TV,should be no resistance at connections.
That should get you started. If this doesn't find the culprit,we will go to + side and controller next.

when i got the 8.6 volts the tire would still spin freely when brakes were engaged, I can hear the other 3 tires engaging (buzzing noise) but none at this tire. when the blowout happen the tread did flop around and dash read trailer fault for a second but the wires look fine up to back of break assembly

how do you tell which wire is the positive and which is the negative, this is the last brake the wires run to the three other tires first

rtaylor0830 wrote:
how do you tell which wire is the positive and which is the negative, this is the last brake the wires run to the three other tires first

If you connect the volt backwards,it normaly reads the voltage as as
- amount analog or simply has the - symbol at top of screen on digitals.
You can also test each wire at rear of drum as you did before and there will be no volts from trailer frame to - wire.

Trailer electric brakes do not have neg/pos specific wires. There are two wires that come from the magnet and one connects to the trailers pos and the other connects to the trailers ground, but it does not matter which wire is which from the magnets point of view. Just as long as one is pos and one is neg, that's all it cares about.

You should pull the drum and inspect the wires inside the assembly.. When my trailer was only a year old, I did my first wheel bearing service and found 2 of my wheels had cut brake wires inside the assembly. I spliced in longer wires and routed them so they would not get cut again.

When I replace the entire brake backing plates 2 years ago (10 year old trailer now) I just cut the 2 wires going to each wheel and when I put the new ones on, just spliced the 2 wires back without knowing (or caring) which wire was which.... The brakes work great! :)

Good luck!

Mitch

MitchF150 wrote:
Trailer electric brakes do not have neg/pos specific wires There are two wires that come from the magnet and one connects to the trailers pos and the other connects to the trailers ground, but it doesn't matter which wire is which from the magnets point of view. Just as long as one is pos and one is neg, that's all it cares about.

You should pull the drum and inspect the wires inside the assembly.. When my trailer was only a year old, I did my first wheel bearing service and found 2 of my wheels had cut brake wires inside the assembly. I spliced in longer wires and routed them so they would not get cut again.

When I replace the entire brake backing plates 2 years ago (10 year old trailer now) I just cut the 2 wires going to each wheel and when I put the new ones on, just spliced the 2 wires back not knowing(or caring) which wire was which.... The brakes work great! :)

Good luck!

Mitch

Howdy Mitch,hope you injoying this bit of good weather as much as we are.
I am and have been a student most my life and am puzzled by your remarks(esp those hi-lited). I'm pretty sure if I don't understand,others and the op don't either. My concure isn't that my procedure was blown out of the tub but that it leaves the op with no other suggestions on systematicly finding the problem with least time and effort. Perhaps if you tell us what you were attempting to add as far as troublshooting,I might better understand and learn something which is realy what Tech Issues is all about. The op was having trouble getting someone to help find the problem without tearing it apart and throwing parts at it. So much in fact,he posted once before and noone responded. As you can see,I average posting about once in 18 days where you do so about 27 times. That doesn't mean I only drop in ever 18 days. I just don't post in order to increase my count and be declared some sort of expert based on post count. So help me out here. Did you mean mags instead of wires? And are you informing the op that while using a VOM,it [COLOR=]doesn't matter and his meter doesn't care if he checks resistance in the circuit if voltage happens to be applied at the moment? I would think that could smoke his meter and wouldn't tell him much unless he knew wherther he was looking at a grounding or possiably some other issue.
Thanks for your time and I respectfully await your response.