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-   -   Brake Wiring Issues (http://www.fiberglassrv.com/forums/f72/brake-wiring-issues-76892.html)

fieldphoto 10-02-2016 10:04 AM

Brake Wiring Issues
 
For those who have been following along in a related post, we FINALLY got the old brake off. *phew*!

NOW.
I tested the electrical wire coming from the left brake before I even took the old brake off. I was getting a solid reading.
Now? of course... nothing. I can hear the left brake clicking on, but there is nothing on the right side. So, I cut the wire and tested again, nothing. Par for the course on this project, which is 'if it can go wrong it will'... lol.

So, either there is power and I am not using the volt meter correctly (very possible, but I think it is right! besides, there isnt the 'clicking' noise)

Or, I mysteriously have a disconnect issue now. Any suggestions on how to chase down the problem between the two sides?

Am I correct in that I should be able to activate/test the brake assembly before putting everything back together anyways?

Thank you all for your continued support in this project! I will be excited to move on to other issues.

fieldphoto 10-02-2016 12:05 PM

ok, I got up under the trailer, and now I am even more perplexed.

It appears that I have one cable coming from the tow vehicle, that comes down thru the fiberglass, and then connects to a SINGLE wire that runs full length left to right to each brake.

There is a Quick Splice Connector that splices in the power to the brake power line... but, as I see it, the power IS making proper connection with the brake power line in the quick splice connector, because the left brake is working.

So how is the right brake not working? IT IS THE SAME WIRE! How is it that I have power on 1 side of a wire, and not the other side? I would understand if there were a connection that might be bad, but there isnt actually a connection.

THE ONLY thing I havent tested is the ground wire connection on the right side. Is it possible that a bad ground wire is causing an incomplete loop and somehow allowing all of the power to be sucked to the right side of a wire and not the left?

I am thoroughly bamboozled. I hope someone can help.

gordon2 10-02-2016 02:26 PM

Quote:

Originally Posted by fieldphoto (Post 611451)
...
THE ONLY thing I havent tested is the ground wire connection on the right side. Is it possible that a bad ground wire is causing an incomplete loop and somehow allowing all of the power to be sucked to the right side of a wire and not the left? ...

A bad ground in the most common problem in low voltage trailer wiring. It never hurts to clean up an old grounding connection.

Thinh 10-02-2016 04:15 PM

After checking good connection, GND, also wiring and problem still exists, then it could be your magnet itself. Open wheel hub that side, using voltmeter to measure voltage while applying brake. If there is voltage drop (b/t 6 to 12VDC, depends on your adjustment of brake controller) and no click---> your magnet toasted, get the new one. Just my thought....

Raspy 10-02-2016 05:05 PM

Field,

You should look for voltage at the magnet that is not pulling in. If its there, you may have a bad magnet or a bad ground on that side. If it is not there, you have a bad wire or connector.

With only one wire, the system must be grounded through the frame. But that is not very good for brakes because there is not a good ground path.

Just do some more tracing with a test light or volt meter. You'll find the problem.

Carol H 10-02-2016 05:32 PM

Quote:

Originally Posted by fieldphoto (Post 611451)

THE ONLY thing I havent tested is the ground wire connection on the right side. Is it possible that a bad ground wire is causing an incomplete loop and somehow allowing all of the power to be sucked to the right side of a wire and not the left?

I am thoroughly bamboozled. I hope someone can help.

A poor ground wire on the brakes can cause all sorts of unexplainable issues. Including and not limited to only one brake working, both brakes working for a while and then neither working. Ask me how I know that! :)

fieldphoto 10-02-2016 07:48 PM

OK, well...
I ended up rewiring the whole brake system. Sounds complicated, really wasnt.. i mean, we're talking about 1 wire and a few connections.
1. replaced 8ft wire that runs left to right to each brake
2. replaced crimp connector that connects power from tow vehicle to wire described above
3. trimmed and reconnected all wires from power line and ground to brake. there were some 'extensions' in place- trimmed those out so there is only 1 connection per line
4. replaced the aluminum ground connector that connects the ground to the vehicle. It was an inexpensive part at home depot, figured if I was replacing everything else, might as well replace this.

I am not sure what solved the problem, there were no 'obvious' issues (loose wire, cut wire, bad connection) but something in the loop was bad. Probably the grounds.

Several of you suggested here or in PM to replace the ground to trailer with a full ground wire running up to the front. I did not see your message in time, but thank you for the suggestion! At this point I am sticking with the manufacturers design, just replaced the parts. If I have the same problem again in the future, I will look at a different long term solution.

Why did I replace the whole system? Well, 3 reasons. 1. its a simple system, so if you are replacing 2-3 connections, might as well do it all- hopefully this will save me some time preventing further issues. 2. I didn't really know where the issue was exactly 3. To be honest, I couldnt figure out how to test the power to the brakes once the circuit was broken. The brake controller only sends power to a complete system (or you get an error) and I wasnt sure how to work around this. So, I went with what i knew.

Anyways, thank you ALL for your help. This includes the wiring, the removal of the bolts, and the repacking of the wheel bearings (which seems so long ago now!) I have learned a ton about this part of the trailer, and I am really grateful to you all. Now on to more fun projects!!

Darwin Maring 10-02-2016 07:51 PM

I double grounded my brakes. One wire from left to right and a ground to the frame on each side. Reason: Should I get a bad ground on one side, both brakes should work.

Byron Kinnaman 10-02-2016 07:54 PM

Since the brakes are the ONLY system that uses the frame of the trailer as part of circuit the problem is most likely the connection from the brake magnet to the frame. I've had this problem about 3 times in 11 years and expect it'll crop up again.

Joe Romas 10-10-2016 05:43 AM

For dependability the ground for the brakes should be the WHITE negative wire and not the frame.

As Byron points out the frame ground is not dependable.

Problems crop up at the most inopertune times:-(

All the other 12 volt items, lights, water pump fantastic vent fan and so forth use the WHITE wire too.

Joe

Darwin Maring 10-10-2016 10:53 AM

Brake ground wiring to the frame on each side and also connected back to the white wire on the converter ground lug. The white wire on the tow vehicle connected to the frame and also to the white wire on the connector. To many people rely on the ball hitch to make a ground connection and that is not enough because from time to time there is no electrical connection at all.


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