Troubleshooting Pollak Trailer Connector Adapter Not Working With Kioti DK5010 Tractor

Updated 12/22/2025 | Published 10/13/2024

Products Featured in This Question

Pollak Trailer Connector Adapter - Vehicle End - 7-Pole Round to 7-Way Blade

(191)

$35.24

10 Gauge Wire - Blue Primary - Per Foot

(108)

$1.61

Buyers Products Trailer Connector Adapter - 4-Way to 7-Way RV and 4-Way Flat

(200)

$20.66

12 Gauge 7 Conductor Jacketed Wire - Per Foot

(521)

$10.90

Pollak Heavy-Duty, 7-Pole, Round Pin, Trailer Wiring Connector - Trailer End

(125)

$20.24

Pollak Black Plastic, 7-Pole, RV Blade-Style Trailer Socket - Vehicle End

(350)

$14.63

Question:

I purchased this adapter to connect a Big Tex dump trailer with a traditional 7 pin connector to my tractor, a Kioti DK5010. When I plug in the adaptor, the trailer brakes are locked regardless of the position of the tractor brakes. What is the fix?

asked by: Forrest

Expert Reply:

Hi Forrest; because of the way an agricultural 7-way is wired the # PK12-724 is not a good solution. The best thing you can do is run a 7-way blade and connect straight to the trailer. Right now you don't have a brake output pin and it sounds like 12V power is carrying over so the brakes are constantly activated. Also, your tractor will have separate brake light and turn signals which won't work with the Big Tex trailer.

To accomplish this you can use the # 337TC1474P along with the # HM48847. You can tap into the functions on your 7-way round and then the converter will combine your brake and turn signal functions for the trailer. After that you can run # 10-1-1 for the brake output wire up to your brake controller.

I attached a few wiring diagrams below to help with this process. Basically you're adding a 7-way for a brake controller but tapping into the existing 7-way for everything aside from the brake output wire which you can run to the cab of the tractor.

I did write this assuming you actually wanted to use the brakes on the trailer. If you don't care about using the brakes I believe removing the screw on the adapter will let you access the pins in the back of the connector so you could pull and cap off the wire from the brake output pin.

You could also return it and make a custom wiring harness using # PK12-707E, # PK11700, and # DW04914-1. You can wire this however you want and make sure nothing runs to the brake output pin. However, whether you try to modify the existing adapter or make your own you will still need the converter # HM48847 for the lights to function properly.

expert reply by: Robin H

7-Way Wiring Color Code.
(click to enlarge)

Brake Controller Installation Wiring Diagram.
(click to enlarge)

7-Way Adapter Wiring.
(click to enlarge)

Robin H.

12/22/2025

Hey Forrest, how did things go after trying the wiring setup with the converter and new 7-way connection for your Big Tex trailer? Your results could really help others working on similar tractor-to-trailer wiring issues.