Recommended PWM Filter to Address Running Light Error on Trailer Pulled by a GM Truck

Updated 12/29/2025 | Published 01/14/2023

Products Featured in This Question

7-Way Vehicle Power Adapter for Furrion RV Observation Camera

(666)

$65.89

12V PWM Filter for RV Backup Camera Systems - Hardwire

(252)

$67.94

Question:

I have a 2022 GMC 2500 with the camera problem. I bought the Furrion adapter and the camera works but my screen still reads running light error. This Voyager part VGR64VR seems like it would work but unlike several of your installation videos I have a 2023 Grand Design Reflection. Do you have any idea if there would be anything prohibitive in the wall that would create installation problems?

asked by: Henry K

Expert Reply:

You are correct the 12V PWM Filter for RV Backup Camera Systems item # VGR64VR will solve your problem. The PWM Filter is basically a capacitor that provides your camera with the necessary power that GM has decided not to provide through their 7-Way connector.

I have not heard of any issues that would cause this filter to not work correctly with the new 2023 Grand Designs. I have linked an installation video we did on this part below. It's on a different trailer abut the steps will be the same.

expert reply by: Jerred H

Todd

10/13/2025

So I installed a PWM filter in my junction box on the trailer to cover all 3 of my cameras that run on the running lights circuit. The cameras work great but my 2024 Silverado keeps telling me to check the running light wiring. Presumably because it doesn’t get a return signal due to the filter. Is there a fix or is that just a lesser of 2 evils problem? The running lights are working perfectly well.

Jerred H.

10/13/2025

@Todd That's definitely a new one. You can check the connections and see if somethings lose or your 7-ways dirty but another cause for that warning message on a 2024 Silverado is a recall on the trailer connector due to voltage issues.

Todd

10/13/2025

@JerredH It only happens with the PWM filter connected. If I disconnect it the trailer running light test works fine but the camera no longer works. In either case the actual running lights work fine.

Jerred H.

10/15/2025

@Todd That's good that it still works. Do you have the ability to or have you already tried connecting your truck to another trailer? Trying to run through the possible issues so we can get rid of that error message.

See All (4) Replies to Todd ∨

James W.

12/28/2025

I bought a new 2025 Grand Design Influence 3503GK 5th Wheel and a 2026 GMC Denali Ultimate 2500HD to tow. The GD was wired for a rear view camera But no camera. I ordered a Furrion camera so I ordered one from Amazon. Installation was easy. Two problems surfaced. One is all Furrions are shipped with cigarette lighter plugs. The Denali’s have zero such plugs so that leaves you with USBC or standard USB connections for power. There are is a couple of USB ports and only one USBc port. I am not certain if either USB port in the truck is adequate to power camera monitor. Second problem I am just finding out is this GM PWM on some or all lights in trailer. After installing the camera and monitor, the camera would not sync. Tried lot of different things that did not work so I took the camera down and home and set it up using a 12V regulated power supply to power the camera and they synced quickly and easily. Took it back and reinstalled the camera and it does not work! Found a blurb on YouTube where a guy had a late model trailer late model Chevrolet 3/4 ton and had the same problem. He had a solution that involved installing a switch in the power to trailer line that essentially switched the battery line and the tail/clearance light wiring. Seemed reasonable, so I decided to try that only to find the junction box where the wire from the tow vehicle connects to the trailer is not accessible without taking the thing apart! So how is this problem addressed? Going on first longer trip next week and I am a bit nervous since we have n been running class a large diesel pushers all of which have rear view cameras! Thanks Dave

Jerred H.

12/29/2025

@JamesW To power your monitor you'll need a 5V USB to 12V DC step-up converter cable, which we do not carry. That USB port in your Denali will be sufficient to power the monitor. The 7-Way Vehicle Power Adapter for Furrion RV Observation Camera item # FR87PR will solve the GM PWM issue. This plugs directly into your 7-way and provides the correct voltage to power the backup camera. If you don't want to mess with the 7-way adapter item # FR87PR , you can install the 12V PWM Filter for RV Backup Camera Systems item # VGR64VR. It'll wire in directly behind the backup camera.

James W.

12/29/2025

@JerredH You say i need a 5V to 12 VDC step up converter cable then "that usb port in your Denali will be sufficient to power the monitor". Sounds like you are saying the USB port is providing 5VDC and in order for it to work, I would need a step up converter cable" With that being said, how is "That USB port in your Denali will be sufficient to power the monitor"? I am confused!