Ok guys I’ve got a weird one. So 2010 f150 5.4

I don’t drive the truck often since I have a work vehicle. When I drive it there’s no issues and then all of a sudden dead battery. I’ve had the battery tested and they said it was good. After sitting for a week it starts up with no issues every time but if I drive it to the store or something sometimes it’s dead. And other times no problem. Jump it and good to go for the rest of the day. Recently I have the message that my tpms sensor doesn’t work anymore. Now today I went out. Started right up. Drove 20 minutes away. Dead. And now it’s saying I have 0 miles to empty which has never happened before. I had about half a tank so I know I have fuel and drove home the 20 minutes no problem. Anyone have any idea where to start??? Thanks for the help.

 

Welcome. Have you tested the alternator?

 

No I had only had the battery tested. Just seems weird and doesn’t always happen

 

This sounds like a loose connection. The next time it wont start, try wiggling battery cables and see if it fixes it.

 

so I’ve definitely tried that. I’ve cleaned both connections and they were both tight last time

 

Try cables on the BCM, also.

 

I'm partly "stumped" but what I would try:

Next time it is dead.. measure the battery voltage directly (on the terminals).. If it reads 13+ then it is a bad / intermittently bad connection.

If the battery voltage is low then it is the battery and or charging system.

Put a digital voltmeter in the cigar / power point, so you can monitor while driving.. with the alternator (engine running) working it should be above 14 V.

Armed with this data it may lead you to what is going .

Keep us posted.