Hello all.
This is my 1st post on this forum, so I apologize if this issue has been addressed. I have spent 30 minutes or so looking around and did not find this exact issue.
My f150 has a 5.0 w/auto transmission. 6ft bed. 13,800 pound weight rated towing capacity.
This past week I spent time towing a 7400 pound travel trailer from Oklahoma City to Southeastern Alabama and experienced an electrical issue. As the day wore on my truck started having issues dragging while starting. I had to jump start it a couple of times. After disconnecting the truck and allowing a 30 minute wait, the truck would crank just fine. Seemingly an electrical draw from the trailer is running down my battery while towing.
I am not sure where to start looking for the issue, although I started with the truck battery. I disconnected the negative side with the engine running, and it kept running, so the alternator seems to be fine. Where should I check next?

2018 F150 5.0 6ft bed 2021 Open Range 275RLS

 

How long have you had the truck? Has it always done this? How long have you had the camper? Does this ONLY happen with the camper hooked up to the tow vehicle? Is it possible that the camper is drawing 12v from the truck's system to try to run an electrical load inside?

 

I bought the truck new. Just went and picked up the camper. It's my first time towing this camper. I never had this issue with any other travel trailer I have towed.
I will start with the travel trailer ground and work from there, although all the lights work fine when I plug the camper into my truck to tow.

 

So I have read of this happening, and it was mostly on 2018 with 5.0. Seems there was a bad batch of starters. They get heat soaked, under the extra stress of towing, and need a few minutes to cool. Replacing the starter typically is the answer. Here is one link to the problem https://www.f150forum.com/f82/2018-f...towing-493639/

 

Thanks. I will check it out after Church.

 

You've probably already checked this but if not, make sure your fridge (if on while towing) is not set to run off off DC. That will kill your battery quickly, even while driving. Good luck...I hope you get it figured out.

 

Just so you know, disconnecting the battery while the engine is running can easily fry your alternator. Use a meter next time.

 

Thanks, I will make sure both are off next trip.

 

Have read/watched about several vehicles with this problem. Will definitely keep an eye on this. Best/Least expensive solution seems to be a thermal wrap.