I have a 07 xlt 5.4 with a problem. This started in Jan after truck would not start without a jump. Took it to dealer and they replaced the battery, lasted about a month and then again had to jump start. Back to the dealer and they said everything tested ok but that my power wire for the amps I installed was causing the battery to draw 200ma with the key off and the spec calls for 50ma or less, the norm being around 20ma. I removed the fuse to my power wire at the battery as to remove my sound mod from the equation and tested the amp draw, after a min or two the draw was at 205ma after serveral rechecks and 30 min later the draw dropped to 19ma.

After opening the passenger door and then closing it I rechecked and it went through the same draw down routine 205ma 30 min then 19ma. Same thing if I opened the driver door and closed it. My ? is what would be turned on and take a half hour to turn itself back off? Is this kind of draw enough to take down the battery over time as I don't drive it much and it does set for 3 or 4 days at a time. Even with the fuse replaced for my power wire to the amps it still did the same routine. Less than 3k on the miles and still under warrenty but dealer is saying it's something to do with my amp mod. Any ideas?

 

I am having the same trouble, and I am going to work on it soon.

My procedure is disconnect the positive lead and use a volt meter to connect it to the battery. One by one, I am going to start pulling fuses until I find the parasite.

 

I know you said it is an '07 but is the alternator going bad? We traced a similar problem in a car and it came down to the alternator. Replaced it and has not been a problem since!

 

I kind of think it may be the alt too but the dealer said it test ok. At 14.5 v but the gauge on the dash is just a little past the mid point while running. I asked about the amp test on the alt and they said the couldn't check the amps. I think you have to remove it to test the amps and they didn't want to do it. If I put a charger on the battery and fullly charge it, it holds up for about a month so I think maybe the alt does not keep it charged.


I used the neg cable on the battery for my testing. One lead clipped to cable and the other on battery post itself and then slid cable off post while keeping the test probe on the post. 200ma seems high for that long of time but can't figure out what is causing the drain.

 

I have an 06 with that does the same thing. It won't start after 2 days idle. Carried it to the dealer and they said everything was fine and my streamlight flashlight that I have wired in to keep charged was causing the drain. None of my previous trucks did this with the same light. They told me to rewire the flash light so that it charged when the ignition was on.

 

If your rechargable light's battery is failing, then it will cause a constant draw. I have heard of it happening a lot with police vehicles. Try replacing the battery, I replaced the batt in my mag light and it did help a bit.

 

200mA for a 1/2 hour then dropping to under 20mA is normal. It should also pulse a little higher as the PATS light on the dash flashes.
By opening the doors you restart the timer for powering down all the modules. The timer is in the instrument cluster.

 

Isn't that the battery saver and not the normal shut down? I have a door light problem and it causes my battery saver to kill all power until I open and close a front door. No interior lights or oem accessories.

 

Well here is where the Ford service manual is a little vague. I believe it states it can take up to 40 min. for everything to shut down.
By opening a door you wake up the modules and the 40 min. starts over.
The instrument cluster is what makes this all happen, it has the timer in it and it controls the battery saver relay. If a interior light is staying on the draw on the battery will be much higher then 200mA.

 

While on the subject I am going to high jack this a little.

I pulled the dome lights and replaced the cargo lights. So all I have running is two 194 (say 3 watts each) and two 5 watt 194 style bulbs. So I have 16 watts or just over an amp draw from the lights. So I am looking at a 1.5 amps draw for normal (not really normal, but what I should expect) right?