Wiring Issues for 2023 F150 Toad

[johnnietexas]

I'm in the process of setting up my 2023 F150 to flat tow and I'm curious as to how others got the brake light wiring to work. I've got truck taillights wired up to the motorhome no problem, but the issue is with the supplemental braking system. When the truck brake pedal is physically pressed, the brake lights override the blinker signal coming from the motorhome. In the past, roadmaster provided a simple fix for this called a brake light relay. However I can't for the life of me figure out how to install on a 2023 f150. The wiring is different, and the truck doesn't even have a traditional brake light switch under the dash. No one has a how to video, and I've read some comments on etrailer website indicating that you can't use truck taillights at all when flat towing the new f150s. How are others working around the brake light issue?

[Psneeld]

With the worries of electrical issues and coming out of neutral tow when towing 4 down.... I ran a separate set of trailer lights (pulled wire through frame of pickup) to rear of pickup. With plugs at the terminus and on the set of trailer lights, they are easy on, easy off when not towing the truck.

The biggest trick is figuring out how to mount them temporarily on the back of the truck. I have used 3 different configurations so far as I had ladder racks which made it easy but took them off and now on my second tonneau cover.

[JohnArch]

I use the NSA RV Products Ready Brute tow system for my 2021 F150. I purchased the complete light kit for my system from NSA. It has additional bulbs that need to be mounted and wired to the 6 pin plug for the system. This does not use your truck battery but runs off the pigtail from the motorhome to the truck. All instructions are included. I have been towing with this set up for 3 years with no problems. Putting the truck into flat tow mode is done from the steering wheel and like a previous poster, I copied and laminated a copy I keep in the glove.

2015 Entegra Aspire

[MikeyG]

I’ve been towing my 2022 F150 Platinum since it was new. I’ve had intermittent problems with the battery going dead even though I had a Roadmaster charge line installed. I have not had a problem with the transfer case shifting out of neutral tow, but then again, the battery was low enough that I needed to jump it to start, but it may have not been “dead” enough to trigger the transfer case to shift.

I believe there are so many parasitic draws on the battery that the Roadmaster charge line just wasn’t enough to keep up so I purchased the RVI Towed Battery Charger.
Dutch Star Don recommended a battery minder on another thread, so I bought it as well. Here is the Amazon link. https://a.co/d/7b9yqwf
Both the RVI charger and monitor sending unit have to be installed before the BMS on the negative post of the truck battery or else it won’t work.

I was concerned that the BT battery monitor would not reach the driver’s seat, but it works fine in my 40’ coach. I can now monitor the truck’s voltage and SOC while towing. I get a voltage range from 12.2V to 13.5V when the RVI charger kicks in. I have noticed that if I leave the truck unlocked (Which defeats the perimeter alarm) I get an erosion of the SOC. If I defeat the perimeter alarm in the alarm settings and lock the door, the SOC will increase as I drive. The only explanation I have is there must be more parasitic loads when the doors are unlocked, but no proof that is the case. If we stop for the night, I take the truck out of neutral tow, run it for 15 minutes, and disconnect the umbilical from the coach. I have also heard that Ford has a software update that will turn the electric brake booster off when in neutral tow, but I have not found a dealer that can confirm that. I may try pulling the brake booster fuse and see what happens with voltage and SOC.

Someone mentioned a problem with the brake/turn signals. When I set my truck up, Roadmaster said that I needed to wire the towed light setup to the trucks parking LED lamps and not the brake/turn lamps. They are not as bright as the truck’s brake lamps but when my AF1 depresses the brake pedal, the brake lights do illuminate.

The procedure to shift into neutral tow as others have noted is more complicated with the Ford than the setup with my wife's Jeep GC, but not difficult. I too have the procedure printed from the owners manual and it lives in my center console.

Hope it all works out for you.
Cheers.

[Dutch Star Don]

Originally Posted by johnnietexas

I'm in the process of setting up my 2023 F150 to flat tow and I'm curious as to how others got the brake light wiring to work. I've got truck taillights wired up to the motorhome no problem, but the issue is with the supplemental braking system. When the truck brake pedal is physically pressed, the brake lights override the blinker signal coming from the motorhome. In the past, roadmaster provided a simple fix for this called a brake light relay. However I can't for the life of me figure out how to install on a 2023 f150. The wiring is different, and the truck doesn't even have a traditional brake light switch under the dash. No one has a how to video, and I've read some comments on etrailer website indicating that you can't use truck taillights at all when flat towing the new f150s. How are others working around the brake light issue?

Just some thoughts.....did you use one of the premade brake light wiring systems that is plug and play or did you wire in diodes?

With the truck connected, let it sit for about 10 minutes and then see if you have the issue. The truck will shut down all systems after it's parked for a short time and may solve your issue, as long as you don't open the door or turn on the ignition.

Until you can get it figured out, your brake lights will still work, you'll just lose the turn signal, but it will still be visible on the rear of the coach.

Lastly, you could add some small lights to the lenses of the truck. I did that on one years ago, I was able to drill into the lens and install a double filament bulb. They also make those LED light bars that attach under the tailgate and above the bumper. They work as a taillight and brake light. They're pretty bright and more visible than the OEM brake lights.

https://realtruck.com/p/rampage-led-...t=All+Products

[johnnietexas]

Originally Posted by Dutch Star Don

Just some thoughts.....did you use one of the premade brake light wiring systems that is plug and play or did you wire in diodes?

With the truck connected, let it sit for about 10 minutes and then see if you have the issue. The truck will shut down all systems after it's parked for a short time and may solve your issue, as long as you don't open the door or turn on the ignition.

Until you can get it figured out, your brake lights will still work, you'll just lose the turn signal, but it will still be visible on the rear of the coach.

Lastly, you could add some small lights to the lenses of the truck. I did that on one years ago, I was able to drill into the lens and install a double filament bulb. They also make those LED light bars that attach under the tailgate and above the bumper. They work as a taillight and brake light. They're pretty bright and more visible than the OEM brake lights.

https://realtruck.com/p/rampage-led-...t=All+Products

You were exactly right about the time out feature. Roadmaster confirmed the same. I let the truck sit for 15 minutes without opening the door and it went to sleep. The wiring from the coach can work normally and the truck brake lights don't override when supplemental braking system kicks in. This is the only solution. I already have the diode wiring harness installed in my taillights, so I'm good to go. Thanks!

[Dutch Star Don]

Make sure you run a charge line on the Ford. I towed a 2019 Raptor for five years and ran a charge line. Thankfully, I never had the issue with the transmission failure.

[johnnietexas]

Originally Posted by Dutch Star Don

Make sure you run a charge line on the Ford. I towed a 2019 Raptor for five years and ran a charge line. Thankfully, I never had the issue with the transmission failure.

Roger that. I have installed one. I've read about horror stories of batteries going dead and transmissions being destroyed!