“No trailer connected” With hard wired Tekonsha P3.

[spyro235]

Hi all,
After having some issues with my tekonsha RF brake controller unpairing, and the fact that I had a p3 laying around, I decided to hard wire it in. I have it wired in now, but while my lights all work, the brake controller only displays “no trailer connected.”
I’m pretty darn sure everything was coded right, as I had the RF functioning for about 2000 miles. Coding was done by Codemycar in NJ.

Upon install I found the p3 didn’t have power, so I checked the 30a fuse- blown. Replaced that, and it’s giving the p3 power now, but only shows “no trailer connected”. Fuse is ok, and has not popped.

I triple checked my wiring. The colors all match up as they should, used 4x14g wire to extend it. Snipped the BMW connector, wired in the 14x4, and put the tekonsha connector on the end of the extension. Again, unit is powered, so I assume the ground and the positive are working at least.
I’m sure the trailers brakes are good, as they worked in September when I parked the trailer. That was at the end of a 2500 mile trip and the brakes worked the entire time. Wiring is all inside the frame- trailer is a big Tex 18’ car hauler.

Any ideas how to troubleshoot? What is the tekonsha looking for to see if there’s a trailer attached?

[m3buzz]

Not sure this will help, but you mentioned ‘unpairing’ so possibly going back through the pairing process - using a domestic truck’s connector, since pairing with a German vehicle won’t work ( at least that was the case a few years ago when I paired mine) - might do it. Good luck.
I just had to recode my +AHMU module back in following a dealer software update, but before I did that, the trailer lights wouldn't even come on. Sounds like your coding is stable.

[spyro235]

Tried with a domestic truck. No pair, and after trying on 2 different domestic trucks, I decided to just hard wire.
Coding appears to be totally OK, as all lights and various stuff works.