No brakes

[hyperactive]

I just put 4 new complete lippert 12" self adjusting brake units on my 5th wheel and now I get the check trailer warning on my truck . All was fine before, I did accidently cut the wires that go front the front axle to the rear and could of switched them right to left. I thought as long as you had one of each wires hooked to the magnets it should be correct ( no positive or negative) I used the quick grease filled connectors that they sent. Where do I start and how do I find the problem ? It's a 2018 with 20000 miles on it. Another 5 minute job that will take 2 days to fix .

[GHen]

Wires should not make a difference, like you said, just need two to each brake.

[Jagiven]

I would double check your wire connections, including ground. May just have a bad connection.

[Rustic Eagle]

Just a thought.., but worst case scenario,

The brake wires that travel through the inside of the axle tubes are prone to wire insulation wear exposing wire strands to the inner axle tube walls which can cause a brake system short (ie: Check Trailer Wiring)...... been there, done it.

It's possible that while making your new wire connections the wires in the axle tube(s), if previously compromised, may have been re-positioned creating your present issue.

Jiggle the wires at the axle tube entry point and see if your 'Check Trailer Wiring' status changes.

If the wires in the axle tube(s) are the root cause, refer to Post #235 here (my fix):

https://www.jaycoowners.com/forums/f...-51005-13.html

Bob

[hyperactive]

Now I am wondering if the wires that run thru the axle tube could be shorting out , I did slide them side to side when making the connections. I read other people had issues where the insulation wore thru.

[hyperactive]

Is there an easier way to check the wiring other than using the truck ?

[16WhiteColly]

Best to remove the wires from inside the axle tube and zip tie them to the outside of the axle tube. No chance of wire chafing and shorting out.

[Rustic Eagle]

Originally Posted by hyperactive

Is there an easier way to check the wiring other than using the truck ?

I used a multi-meter at my TT's 7-pin connector (@ brake & ground) and found that I had a fluctuating amp resistance when jiggling the wires in one of my axle tubes. Had my BIL monitor the meter while I was under the TT.

Root Cause:



Bob

[Jagiven]

Originally Posted by hyperactive

Is there an easier way to check the wiring other than using the truck ?

.

I like to start with the easy items; Have you checked your 7 pin connector at the TT and TV? Might have corrosion at that connection. With a helper you might be able to can check the brake connection on the TV side with a multimeter. I know on my external brake controller, is proportional to my TV speed. if my TV is stopped, it basically shuts off the power to the TT brakes. Not all are this way. This can make testing the brakes at home difficult.

To apply power to the brakes without the TV, make a small jumper wire. Place the wire into #2 aux power slot and into #4 Brake slot. This will apply 100% braking power to the magnets. It is fine to do this, I would not walk away for long periods with the magnets energized, as they heat up.

A multimeter is a great tool. To test the hot side, pending on your TT, you maybe able to utilize a wire splice location prior to the axle. However I expect you will need to create a long test lead, from your 7 pin to reach the axles. To check the ground side, touch the probe to ground side lead and the TT frame in the area (not the axle).

The reason to check at the frame and not the axle is the axle floats. I have never heard of an issue with a poor ground between an axle and the frame. There should be good solid points, grease, wear, rubber bushings, etc. can insulate the metal components in this floating joint.

Start with the easy items.

[hyperactive]

I used different connectors and moved the wire in the axle and to the out side of the axle and everything works . When I pulled the wiring out of the axle tube I noticed it was wet and looked like it was sitting in water, I am assuming water gets in the holes for the wires when driving in the rain. Should there be a drain hole, the axles are Lippert 5200's , Has anyone else experienced this ? Should I drill a hole on the outboard side on the tube below the hole for the wire just in case some one runs the wire back thru the tube thinking of the burr the drill leaves. Lots of questions I know ! Thanks to all.

[Rock]

Just experienced the no brakes for the first time than all is fine. I just finished the upgraded wet bolt kit and axles moved around a lot. When I replaced my brakes two years ago I took one of the magnet wires and added a ring connector. Placed that on one of the backing bolts. Did that to all four so each would have its own ground. Since I only need one wire inside axle gonna replace what is there with one heavier gage wire and new waterproof connectors. I will bet I have the same problem after 35k miles of a thin wire bouncing around inside the tube. Nice post about using pex outside of axle. I would do the same but just gonna pull one heavier thru axle.

[Rustic Eagle]

Originally Posted by Rock

snip...... Since I only need one wire inside axle gonna replace what is there with one heavier gage wire and new waterproof connectors. .......snip

I'm not well versed on 12V "electric" brake systems and associated brake magnet amperage draw requirements...., but you may want to confirm if installing a heavier gauge wire between the respective pair of magnets if it will compromise magnet operation.

Just thinking out loud here......

Bob

[16WhiteColly]

I believe etrailer recommends replacing the cross wire with a 10 ga. wire. They sell it by the foot, that is what I used, it is a two wire, looks like residential Romex.

[Rock]

Look what the gage wire is that comes out of bottom of trailer. That heavier gage goes down to half the size thru the axles. Gonna run same trailer gage thru axles. That way all four brakes will have same gage connected to the magnet wires. Everything should than be equal. I have always noticed left brakes hotter than right shot with a gun.

[curver900]

Originally Posted by Rustic Eagle

I'm not well versed on 12V "electric" brake systems and associated brake magnet amperage draw requirements...., but you may want to confirm if installing a heavier gauge wire between the respective pair of magnets if it will compromise magnet operation.

Just thinking out loud here......

Bob

only a smaller gauge wire could be impact... so if you are running 10g and you go to 16g (smaller diameter wire) you could have issues including overheat of the wire. If you went to 8g (bigger diameter wire) no issues... you can go up in size but you should never go down in size... the longer the run the larger diameter wire required... resistance is your limiting factor in length with regards to diameter.. there are allot of spreadsheets on this available.

[Rock]

I know that, that is why same gage from pin box (that drops down from bottom of trailer at axles) all the way to each magnet wire. Everything will be the same.