I have a 2005 Ford Expedition XLT that was presenting a dead battery or labored start problem. Autozone tested the battery and said it was OK. I used a multimeter on the battery and saw that the alternator was charging fine.

I then conducted a parasitic drain test on the battery and discovered that there was a 690 mA draw on the battery. I began pulling fuses one at a time to isolate the circuit and found when I pulled Fuse 21, the draw lowered to acceptable levels of less than 10 mA. Fuse 21 is a 15a fuse that says "Instrumnt Cluster (B+), Interior (courtesy) lamps, Puddle lamps (outside mirrors)"

My question is this: Does anyone have any ideas what could be on this circuit drawing these mA's when the truck is off? I have kept the fuse out and the truck has been starting fine.

Side Note: I did notice that the "Puddle lamps" were not working prior to the fuse pull. Can there be a short in that circuit causing the lights not to work and also the mA drain? Thanks in Advance....I will have a few more questions about this nightmare of a truck after I resolve this issue.

 

Seeing as how the lamps don't work and removing that fuse solves the problem that would absolutely be the first place I would look.

 

After a year of looking, testing, disconnecting the battery, jump starting it twice a day we finally found the source of the draw!

It was the rear wiper motor it was a huge draw, probably trying to park constantly. I disconnected it and haven't had ANY battery issues since (over a year)

Thought I should post in case anyone else has the same issue.

Related: You can't just unplug the connection to the motor because there is a tie to the front washer pump. I had to cut the motor wire.

 

That's a very common source.

 

Cutting the power wire isn't fixing it. Fixing it would've been removing and repositioning the wiper arm so that the motor could reach the park position. Then you'd still have a working rear wiper.

 

To the left of the steering wheel there is the **** that works the lights and high beams, directly to the right of that there's a little stroller wheel like you would find on a mouse on a computer. Sometimes if you leave the interior lighting dimmed all the way up, which happens when you scroll that little wheel upwards until it clicks, you will find yourself with a couple random lights stuck on including a passenger side mirror night light which can be hard to spot sometimes. Also other courtesy lights. Easily fixed, every time you park just scroll the Little wheel thing downwards. No overnight drain

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