Guy1337

• 2014 FX4 5.0 stock
• Batt died overnight
• The night before it died: Parked it at home for a few hours, went to get something out of truck and when I opened door the radio started playing. I turned off the radio and closed door
• Removed batt, trickle charged 100%
• Reinstalled, batt didnt die over night
• Removed neg terminal, put multimeter NEG lead on NEG terminal, POS lead on Negative connector. I hear a click from engine area and get 2.87A for about 10 seconds then it goes down to 1.27mA.

Is this normal drain or do I have a problem?
Will keep searchin online in the mean time, will update.
Cheers fellas!

Guy1337

Did some more research on the forums and see that parasitic battery drain is quite common on the 09-14. Based on my findings these causes are commonly:

1. multiple different connectors can be corroded
2. atleast 2 guys had the same exact wire single wire loomed in a bundle inside engine bay being damaged causing drain
3. one guy mentioned it's common that wires that inside interior behind driver underneath the trim panels that are commonly knicked from factory
4. bad solder joints in the gauge cluster which caused cluster to light up

None of these issues mentioned the weird radio problem i'm having though.

I haven't been able to confirm if the truck should audibly make a click noise when I check DC amps across positive terminal and disconnected negative cable. Nor if the amount of amps fluctuating is normal.
The first night after recharging the battery the radio issue happened when opening the door.
As a fix for now until I track this down: what I have done is just manually turn off radio before exiting truck and the battery hasn't drained down so far.
Will update

Ricktwuhk

You need to reset the BMS, you may have read that.

Guy1337

Thanks, just searched it. Not properly reseting BMS can cause the radio to suddenly start playing by simply opening the truck door?
If I understand correctly, since I removed the battery from the truck to charge, the BMS won't know the state of the battery and needs to be reset?
Without scan tool; you can reset it by not opening/using/keyfobbing the truck for 8 hours it says. Does that mean I need to completely disco battery again, wait X amount of time then reconnect it and wait 8 hours?

I read that you can disconnect the current sensor (black plastic ring) that is on the NEG cable and not have to deal with resetting BMS, is this correct?

Ricktwuhk

Lock doors for 8 hours.

As to the behavior that a vehicle has when the vehicle thinks the battery is below some level, I don't think that anyone can accurately answer that question. People have posted all sorts of weird things that have then been resolved by a new or fully charged battery.

Guy1337

Thanks, it mustve reset itself by now in that case. I will try leaving radio ON before turning truck off tonight and see if the previous problem happens again.

found this thread which has a ton of great info for anyone who may be reading this in the future.
How to reset BMS: https://www.f150forum.com/f38/replac...ew-way-231938/

Thanks again for your time Rick, cheers.

Russell Shettle

Are you sure about that reading? 1.27ma? Reason is ask is: I've read that the normal parasitic power draw should be between 50ma to 85ma. I could be wrong.