Troubleshooting Tekonsha Primus Brake Controller Not Showing Trailer Connection

Question:

I have a primus brake contour that I had on my 06 Sierra fitted with the factory brake harness I have taken off of the truck and installed it on our 05 Yukon I figured no brained however after I installed it on the Yukon I get the two dots in the readout which says it is power with no trailer hooked up. Any suggestions on what to look for I am kind of lost here. Thanks any help would be great.

asked by: Mark K

Expert Reply:

The Plug-In Wiring Adapter # 3015-P that you used to install the Tekonsha Primus IQ Brake Controller # TK90160 on your 2006 Sierra is indeed the same harness that is designed to work on the 2005 GMC Yukon. Unplugging the harness from the Sierra and then connecting it to the factory port on your Yukon, assuming it has the factory 7-Way connector, should be all that is needed to move the brake controller over to this vehicle.

After installing the controller, the display on the unit should read "n.c.", which means there is power to the brake controller without a trailer connected. After 15 seconds, the display will then change to the two dots (. .) that you referenced. Is this showing up when you have the trailer connected?

If this message is displaying when you do have the trailer connected, I first recommend taking a look at the vehicle and trailer side connectors. Check them for any debris or corrosion that might be preventing a secure connection, cleaning them out as needed.

You can also test the brake controller itself by severing the blue wire several inches from the back of the controller. Use a circuit tester like # PTW2993 to test the end of the blue wire coming out of the controller. It should only have power when you apply the manual override. If it shows power at idle, then there is something wrong with the Primus controller itself and it may need to be replaced.

Otherwise, if everything checks out fine, you can test the brake output pin on the Yukon's connector. You should again get power here when applying the controller's manual override. If it shows power at any other time or not at all, then there is likely a short somewhere between the connector and brake controller that you will need to track down. Check for any exposed or damaged wiring, fixing when needed.

If you still are unable to locate and resolve the issue, please let me know and we can continue to troublehsoot.