Hi All, I have a 2015 F350 and am experiencing severe battery drain issues. If the truck is left idle for 18 hours it won't start. We have done some extensive testing and found that when the truck has been locked for over an hour it is still drawing 3 amps. After removing one fuse at a time (painful!) we have found that by removing the GPS/Sync?Radio fuse that it dropped the current draw to about 1.3 amps. I still think this is way too high. When it dropped to 1.3 amps it seemed to be varying between 1.3 - 1.9 amps.

Can anyone help with this issue as it is actually driving me insane!

Cheers

 

 

Leaving a truck idle for 18 hours will kill any battery. Next the truck doesn't go to sleep it would appear. If you have the hood open there is some current draw from the alarm system just not sure how much.

 

 

 

 

 

The alternator doesn't put out enough energy just idling there. In order for the alternator to produce enough energy to charge the battery. It has to come off idle.

 

These trucks have lots of things when you first shut the truck off continue to draw power. However after about 15 minuets the truck should go into sleep mode. However the alarm system doesn't sleep Over a 1 amp draw seems like a lot to me. I have heard that there is a plug under the dash bu the emergency brake that may cause problems. They say to unplug it than plug it back together. I have a 15 and don't have this problem. Good luck.

 

Hi All, thanks for your help. It turns out that the Transmission control module is faulty and draining the battery.

 

How unbelievable is that LOL
Glad you found the problem.

 

 

I was under the truck looking for shorts and just happened to notice the module was hot. I unplugged it and the current draw went away. I had some problems with the truck going into limp mode due to some water issues and that module so I am guessing it obviously did some damage to it. Cheers