Troubleshooting Trailer Jack Not Working When Hooked Up to 2021 Duramax 7-Way

Updated 03/10/2026 | Published 04/12/2025

Question:

When I hook my truck up to my Winnebago Minnie the power jack will not raise or lower. However when I hook to a power pole at a campsite the hitch power jack works. I also hooked it up to my buddies truck and worked. Think it’s my truck or is it the camper battery? *when camper is hooked to my truck the brakes and blinkers work. Just not the jack or the jack front light. I have a 2021 Duramax with 2 brand new batteries and my other trailers work on blinkers and brake lights.

asked by: Steven

Expert Reply:

Hey Steven, thanks for reaching out!

What you're needing to fix your problem is the 7-Way Vehicle Power Adapter # FR87PR. GM, in their almighty wisdom, decided to lower the power output on the 12V pin in certain situations so what's happening is your jack isn't able to get enough power. This adapter basically prompts your truck to send out more power at the plug so your jack will be able to work.

Your blinkers and brakes are on different circuits which is why they haven't been affected.

Let me know if you have any other questions!

expert reply by: Jon G

Steven R.

4/15/2025

Unreal! Thanks brother. I have ordered the part and will update once it comes in! I’m glad I asked!

Jon G.

4/15/2025

@StevenR Oh absolutely! Furrion came out with this adapter because their camera system wasn't getting enough power with the new GM trucks and we've found that issue is more widespread than just the Furrion camera system, so the adapter works for lots of different things!