Troubleshooting Primus IQ TK90160 With Fluctuating Voltage Readings After Stop

Question:

Hi, Ive read as much as I can read. Nothing hits the nail on the head. The last few trailer pulls have brought up this issue. I stop at a red light and everything is normal. I go to pull away and the the voltage on the controller starts fluctuating and making the trailer drag. At night Ive watch the front of the enclosed trailer and the taillights are not shining when this takes place. So I find it hard to believe its the trucks brake circuit. I tap the brakes several times and she gos back to 0vdc. There is no issues using the manual button without the trucks brakes to test it. The fluctuating voltage is not fixed. its all over the board at any given time. Usually low though. in the 1-3v range. Any ideas? Im an electrical eng. Get as deep as you want. Thx in advance

asked by: Mike F

Helpful Expert Reply:

For troubleshooting your issue with Primus IQ # TK90160, I recommend starting by checking the brake magnet ground connection on your trailer on each side of your axle. Make sure the connections are bare metal to metal and free of corrosion or debris.

Next, clean your trailer connectors both on the vehicle and trailer side. Use some sand paper or steel wool to clean the connections thoroughly and then use some dielectric grease like # 11755 to keep moisture and debris out of those connections.

If you still have issues after these changes, check your ground connection on the brake controller. If you are still experiencing this issue following that, then I recommend testing your brake magnets. I've attached an article to assist with this.

Let me know if we need to further troubleshoot following these next steps.

expert reply by: Jason S