Brake issues

[Flips]

Greetings,

Hoping someone has had similar brake issues and can help me trouble shoot.

TT: 2016 heartland north trail 33bkss
TV: 2015 Nissan NV3500 tow package
Brake controller: teknosha P2

Whats happening: while driving the brake controller cuts out and gives me an S.H error message. Sometimes the error comes on when I turn but goes away when I'm pulling straight and the brakes function just fine. Sometimes, the P2 doesn't read anything at all but stays at 0.0.

When parked and pressing on the brakes, sometimes I get readings on the P2 right away and sometimes there's a 3-5 sec delay prior to getting a reading that the brakes are being applied.

Sometimes when I press on the brakes there's a clicking sound coming from underneath the steering column.

I drove the TT 200 miles from the dealer to home with no issues. The next day I made adjustments to my pro pride hitch and took it for a test drive. Did well for the first 10 miles of back roads. I took a right turn and was about to enter the freeway when I noticed the P2 giving me the S.H signal. luckily I was able to get out of the freeway and limped home with no brakes. I did stop to check the set up and it's possible that my brake harness was riding low and was bouncing on the ground during turns 😞

Because of the extra foot added by the propride I added a brake harness extension. I've decoupled the connection and gotten close enough to connect to the trailers brake harness. I got the same issues mentioned above so I don't think it's the extra extension.

Any thoughts?

Thanks!

[_tiredTeacher]

Flips wrote:
This is my first experience with electrical issues and I've read to next check relay switches. Gonna do that today after work (although Im not quite sure what to check for a functioning relay switch).

World's simplest relay switch described (I'd draw one if I knew how): Picture a rectangle. There are 4 posts on it. We'll call the ones on the right end 1&2. The two on the other end are A&B. (Wires to A&B are a larger gage than wires to 1&2.) A is connected to a power source, usually directly to the battery positive. B is connected to whatever the relay operates. Post #1 is connected to a switch and #2 to ground. Current to #1 from a switch activates a small electromagnet in the relay closing the circuit between A&B. If the relay is solid state there is no mechanical switch but it tests the same way.
Current on terminal A "on" when battery is engaged.
Current on terminal 1 "on" when switch is activated
Current on terminal B is "on" when current is supplied to terminal 1.

That's it in a nutshell. Have fun,
Teach

[spike99]

I'm not a fan of factory linear design brake wiring. Wish industry would make STAR design using 10 gauge thick wiring mandatory.

For more details:

Factory Linear design - - click here -

STAR design - - click here -

If needing to replace brake wiring (due to inner axle shorts, etc), highly recommend upgrade STAR design. To support brake wiring under the trailer, simply use plastic PVC conduit pipe. re: - click here -

Before and after comparison of linear vs STAR brake wiring design is amazing... And, a do-able DIY upgrade task.

[Flips]

Thanks Teach and Wayne!

I bought a 12V circuit tester and found that everything on the trailer end checks out. I got signals from all the pins. I went to the TV 7 pin plug and got signals from everything except the reverse lights and brakes so the issue is with the van.

I checked all the fuses related to towing and brakes and found one busted. I changed the fuse and still no signals from the brake or reverse lights.

This is my first experience with electrical issues and I've read to next check relay switches. Gonna do that today after work (although Im not quite sure what to check for a functioning relay switch). Maybe just change them all out?

Once I have it working again I'll probably buy a longer harness and swap out the one on the trailer. This will remove the extension and another potential point of failure. Hopefully this will prevent reoccurrence.

Wayne, there was no visible damage on the extender. I checked the exterior for drag signs and there was a little bit where it connects to the TW harness. I removed the screws and checked all the wiring connections on both ends and everything looks intact. Probably got banged hard at one point and messed something up internally.

[WayneAt63044]

SH means the wire to the brakes is shorting to ground. A common place for that to happen on an older trailer is where the wire goes through the axle from one side to the other. On a new trailer, and with your description of the symptoms, I'd start by checking the wiring in the pig tail, especially if it has been dragging. Is the cable worn through where it dragged on the ground? Then check your extension connections. Disassemble connectors to see if all the wires are firmly attached and not shorting to an adjacent pin. If nothing found there, check the end of the cable where it connects to the trailer.

[_tiredTeacher]

Two thoughts. First - in my experience with automotive 12V DC, I noticed when a system is acting up with strange and varied symptoms, it is usually a ground problem somewhere.
Second - Given all the varied symptoms, I would get a pro installer involved. The tech has the tools and knowledge to troubleshoot the installation from on the TV, to the TT and on the TT. And pros have a major advantage in this type of work: they can borrow a new controller from parts, try it and return it if it doesn't fix the problem. You would have to buy it and keep it regardless.
Check all grounds and connections. I'll bet there's an intermittent break in a ground circuit somewhere.

Teach