Racer117

I have dreaded dying battery syndrome. Before I start some serious troubleshooting, I wanted to find out what Ford spec is for my truck, '10 FX2 w/ 5.4L.

I am currently measuring ~78mA after truck has been sitting for about an hour.

Anybody have an official number?

Much thanks, Scott

Marc D

You should be testing volts at the battery not amps. The amperage draw varies too much during operation. At the off position the battery should read 11.9 to 12.4 volts. During idle it should read 13.4 to 14.3 volts. This only tells you if your charging circuit is functional. If you don't own a load tester, pull your battery and take to a box auto parts store and they'll test it for you. You could have a bad cell in the battery. Good luck

MGD

Quiescent current after the truck has gone 'quiet' (all of the systems have finally powered off - delayed accessory power, etc) is typically ~50ma. The newer trucks will draw a bit more as there are more systems.

You seem a bit high but probably in the ballpark. This, as noted, is only applicable IF you have a healthy battery and charging system - if you don't all bets are off.

RLXXI

50mA at most, anything more is excessive.

Racer117

Thanks to all for info. I'm on third battery in 2 years so I'm guessing that's not it. Last battery was also load tested and it was fine. Charging voltage at ~2K RPM is 14.4V. I was going to post another link stating exact details but here's what I've found so far.

Charging system is probably OK. (14.4V when running).

Ground cable to chassis resistance is 1.1 ohms.

Current draw when truck is idle (about 45 mins after turning off) is about 80mA. However, using the min/max feature on my Fluke DMM, there are spikes of current draw of 125mA or so. Not sure how long these spikes go for.

So overall , it sounds like I'm drawing too much current at idle. I played the pulling fuses game and though I didn't pull all, the most likely culprits I could guess at it didn't change the current draw. I tried a few in both cabin fuse box and engine bay fuse box.

When I first got this truck, the battery would die if sitting for more than 3 weeks. I travel a fair amount for work so the truck does sit for a week to a few weeks at a time. And to be honest, I could probably live with that. But the few last times, its been dead in about a week and that I can't live with. Because I have secure underground parking, car theft/burglary isn't too worrisome when I disconnect the battery. And really the only thing I need to do is set the clock and that is simple.

Other than that, I love my truck! It truly drives as comfortably as my previous vehicle, '03 BMW 540i. Oh yeah, turns out you also can't put 2 motorcycles in the back of a BMW!