Hey everyone! I’ve run into an issue with my 2021 f150 lariat. After towing my flatbed trailer (4pin) the battery seems to go dead over night even when the trailer is unhooked? This is confusing because it only happens the nights after the trailer is used. No blown fuses. The trucks battery just goes dead. The first time this happened a trailer brake controlle module light came on. But the last couple times the service stabilitrack light along with the service parking brake light came on. I would take it to a dealer for warranty but the wait is roughly 6mo. Thank you in advance

 

Welcome.

Just to make sure you are thinking of everything, consider if there are any other things that are unique to towing or after towing. It could be something simple that is unrelated to the towing event but you always do related to towing.

Beyond that, I can tell you I have a friend with a 2021 that has the battery die when the truck sits for a few days. It also has issues not being accessible through the app. It has been to the dealer multiple times to replace the modem, the antenna, and the battery. He still has the problem. It typically gives him issues when towing, but that's when he goes to the lake and doesn't use the truck for a few days. I wonder if it is related to your problem.

I don't see how a warranty issue could be 6 months out. I know dealerships are backed up, and maybe there would be an extended wait for parts, but I'd check with a different dealer.

 

thank you for the reply! The truck is daily driven and it only has happened after towing the trailer. So im fairly certain it has something to do with the trailer or something along those lines. I’ve only had the trailer for about a month or two and it has never happened before then. Once I unhook the trailer and leave the truck overnight I come out and the battery is completely drained. No lights on dash or anything. Battery charger says 0% once I get it charged enough to start all the warning lights come on. I thought it was ridiculous to when they said 6mo as well. But is it just a coincidence that this happens only after I pull the trailer or is it directly related. Like I said this happens over night and not over a span of a couple days.

 

I wonder why the trailer could triggering something in the truck electrical?
Buy a "battery monitor" and monitor the voltage is after shutting down the truck. It is possible the truck is not going to sleep (hibernate) after shutdown.

 

Was the battery fully drained when you unhooked the trailer at the end of the tow, or still good then but drained overnight?

 

Hi there, I'd be happy to look into your F-150 battery concerns on my end. Will you send us a message with your VIN and dealership info? I can look into things on my end.
Ford Social Media Team