Why won't my factory 7-pin connector power my trailer brakes?

[dneiding]

I have a brand new 2015 NVP SL with factory tow. I installed my Tekonsha P3 brake controller using the Nissan wire harness. The P3 says 'No Trailer Connected' when I connect the trailer. Here is what I have tried:

1. used a test light to make sure the P3 is putting out power when you manually engage the brake switch - ALL GOOD

 

2. ran self diagnostic on the P3 and it senses the brake peddle being pushed per the output voltage test - ALL GOOD

 

3. applied 12 volts to the ground and brake wires at the trailer end connector and verified the brakes did activate - ALL GOOD

 

4, tested all lights on trailer when connected to the van - ALL GOOD

 

5. used a test light to see if there is power between the 5 o'clock (brake) and 7 o'clock (ground) pins on the van-side 7-pin connector when the P3's manual brake switch is engaged - NO GOOD

 

With test 5 failing it seems like there is a problem with the wiring at the 7-pin connector. I know the brake controller is putting out power (test 1) and i believe it is wired correctly (test 2) so i would expect power at the 7-pin connector but there is none. Is there anything I have to do in order to make everything work with a factory supplied tow option? Any relays that have to be added?

 

Thanks!

 

Derek

[vanguy]

Sounds like you possibly have a short between the brake controller & the 7 pin connector. 

 

Did you test the Nissan wire harness while it is connected to the controller? I believe the harness also supplies the 12V to the controller so might just need to check continuity on the harness.

 

I would also probe the brake wire right before it enters the 7 pin conn. It's possible the conn is faulty

Edited May 8, 2015 by vanguy

[Jerry]

x

Edited July 28, 2015 by Jerry

[vanguy]

You may want to check that all relays/fuses were installed as well.

 

Good idea. Sometimes its the simple things that we take for granted that can drive you nuts trying to figure out.

[dneiding]

You may want to check that all relays/fuses were installed as well.

 

Thanks. I looked at the under hood fuse box and all relays were there. I only intend to spend just enough time to verify the van is the problem and then to the dealer it goes. We already canceled our camping trip this weekend so I am not going to spend a lot of time on it - that's what a warranty is for.

 

I will let you know what I find.

[ASD Dad]

Any update on this?  Just curious how it turned out.

[dneiding]

Any update on this?  Just curious how it turned out.

No update yet. I will probably spend some time tomorrow doing some final checking to make sure I am not missing anything. If not, I will make an appointment for next week.

[Heavy Metal Doctor]

I had similar trouble with the connector on the back of my van, too. It ended up being the body harness connector going in the back side of the 7-pin. Nissan makes it a snap together plug which I'm sure they just tie the unused connector up in the body if you don't get a towing package w/7-pin.  In my case, one of the pins slid back inside that connector when they plugged into the 7-pin causing an intermittent connection to the trailer. It took 10 times longer to identify the problem than it took to seat it correctly and plug it back in.

[TinyStudio]

Getting ready for a dry run today before spring break and also had the same issue with no power to the brake lights or my other lights on the 7-pin harness so thanks for everybody for your posts, I'm going to test this out tonight and see what my diagnosis is. Fortunately I won't have to cancel a camping trip as I was only putting my Thule hitch mounted Cargo Carrier on the back.

Edited March 22, 2018 by TinyStudio

[TinyStudio]

Happy update on my issue, It wasn't Beastie's fault.  The 7-to-4 pin connector I had was faulty, the ground was corroded.

Replaced it with a new one before we left and all works as planned.

Next project... Install my brake controller before the end of April