Ok guys.. a strange one here...

I am a GM tech, so bare with me as I hack through the details.

I bought my X 2 weeks ago on a Saturday. It was dead when I picked it up, due to sitting. No big deal. I live an hour from where I bought it. Drove it sunday and monday no problem. Tuesday, I fired it up, drove to work. It sat about 11 hours, I came out and it was dead. I jumped it. Drove home and put it on a charger overnight. Fired it up wednesday morning and drove to work. Just for good measure I did a charging system check. It passes with flying colors. Park it and come out 11 hours later. Dead. I jumped it and pulled it inside and threw a new battery in it. Should be good to go...

I drove it, and had no problems till sunday night. It sat about 16 hours and was again dead. I put my charger on it overnight again. Drove to work monday morning and grabbed my inductive amp clamp. I use that for larger draws so I know I won't pop the fuse in my meter.

I pop the hood, and lock the doors. Put the meter on it and its showing 9amp draw. Normal till the computers fall asleep and such. It dropped down to 4.8 amps and didnt' drop. I checked it an hour later and it was still at 4.8. So I left it sit and when I'd walk by I'd check it. Once in a while it was reading 0.0. The others 4.8. When I went out to leave for the day it was at 0.0, and the truck started just fine.

It's been a week now with no problems, and the only thing I have done is lube all the latches and hinges.

BUT... last night I was working in the garage and once in a while I could hear what sounded like a motor running for a second or 2 in the clamshell trunk lid. I know it doesn't currently lock, but I didn't think it could or would continue to attempt it.

Any ideas guys? The previous owner said he never had any issues.

 

alternator internal draw?

 

Just an idea:


Does it have airbags and/or a compressor. If it has automatic (filling) airbags there may bee a leak that the compressor tries to fill. If it was connected directly and not keyed source it could run till battery is dead.


None of the above then disregard!!

 

It does not have air ride. Good idea though.

I've never seen an alternator cause a current draw.

 

well if you havent seen a alternator drain a battery then you havent owned many fords.

 

If you're checking with a clamp on ammeter at the battery(s), move the clamp to different locations to try and isolate the offending circuit. Charging cable, CJB feed, etc.

With everything off, and the computers "awake", you should only read a fraction of an amp. 6.0's draw approx 350mA awake, and around 160mA when they've gone to sleep.

 

Industry standard is a drain should be no higher than .04 amp.

When (as I call it) the body control module comes awake it can cause a serious amount of draw. Engine, same thing. A running vehicle usually pulls about 15-20 amps.

I have never owned a Ford before, which is why I'm here. If it was a 89-02 Cummins powered Dodge or a GM, I'd have it fixed already.

But working as an Automotive Technician since 97, I have never seen an amperage draw due to an alternator with the vehicle shut off. I'm not saying it's not possible, but I've never seen it. Engine running I've seen an alternator pull a battery from brand new to dead in 10min run time. But vehicle shut off... never.

 

Alternator diodes can short, and cause a high amperage drain with KOEO.

Have you pulled the fuse for rear wiper to see if it's the problem? Does the rear wiper work?

 

Thank you! Ford must do their diodes different than every one else! Lol no big surprise.

When I tested it last week it passed the diode ripple test on our GM factory tester.... I would think if there was a short it would have shown up there. Again... I could be wrong... lol

 

If I'm diagnosing a battery drain I usually start at the fuses. Anything aftermarket is a good place to start then onto the fuse box. One at a time until you isolate which circuit it is. And in this case it would be pretty easy to pull the alternator charge wire off and see. Like the others have said a 4 amp draw is huge. Should be milliamps. Good luck.

 

So... over the weekend I was working on tinting the back windows on the truck. I kept hearing what sounded like an actuator attempting to move. When I was working on the back window it sounded like it was coming from the wiper motor.

My rear wiper doesn't work.

Can one of you guys try a test for me? Turn the rear wiper on and try to get it to "stick" in a different position than where it parks. I suspect that mine wasn't in the right location and was trying to get there intermittantly causing the wiper motor to drain the battery dead.

Thanks guys!

 

Just pull your wiper fuse, if the noise stops and your battery drain goes away you know where the problem is.

 

On my 04, if I quickly cycle rear wiper switch on/off, it always parks. Even tried to make it stick by pulling key w/door open in the middle of it's stroke.

 

Thanks guys! That's what I needed to know!

I'll just take the panel off and unplug it when I go to fix the door lock actuator.