So I purchased my 05 PSD Ex back in February, and since then I have noticed that the batteries seem to drain exceedingly quickly. The batteries were new from the PO (Costco Kirkland specials) in 12/2008.

I use the Ex to tow my race car to the track. If I use the doors on and off during the morning, the truck will be dead by lunch. If I let the truck sit a week, it will not start. Hook it up to the charger for a few and things fire right up and the truck will continue to start as long as I don't let it sit or use accessory power while it sits.

I know the diesel takes a fair amount of power to start and I have read a couple other posts about the starter going bad and draining the battery, but should I need to worry about this at barely 5 years and 55K? I am still under warranty until December so I can take it in if necessary but still seems like something must be off to drain that fast... ideas?

 

Rather than me typing; here you can read.

Battery Drain Parasitic Draw Testing

 

That is a great article! I kinda new how to check but now it is totally clear!

 

Thanks that is a good place for me to start... I am towing out to the middle of nowhere in a couple weeks and would love to figure this out ahead of that trip. Planning on doing a switched dome light circuit at some point regardless, but those alone cannot be causing the batteries to drain that fast.

 

Well looks like I have no choice but to get down into it. I am currently at home, and my race car and trailer are at the track. Have Qualy in 2 hours but the truck won't start. I had to jump it at the track yesterday, then drove it home. About 12 hours later I go outside and nothing.

Hooked up the charger until it said 100%... turned the key and got one crank, then the click of not enough juice. Charger then said 25% only. Doh. Kinda important to get to the track and be able to tow my car home.

The only blown fuse I ever had was for trailer lighting so something tells me that is where I should probably start looking. The car does have an aftermarket alarm as well and I really don't like the quality of wiring there either. Add in some corrosion on the + terminals and... this thing is making me angry.

Anyway, thanks again for the list of things to check... Will be making my way through it very soon it appears.

 

It sounds like an internal battery issue more than a wiring issue. Honestly, I'd probably just get new batteries but you should get yours tested for internal shorts.

 

I would check out your alternator, it may not be working properly. I know that many on the 6.0 forum have had to replace theirs even after it testing out properly at places like Autozone.

My first set of Motorcraft batteries lasted over 5 years.

 

It was the alternator on mine--along with one bad battery... that ends up toasting the other battery. Maybe the two happened together(?)

 

A non-charging alternator would light the battery light though, right?

 

I would find the issue before toasting more batteries....
my first set lasted 80k+ miles and this 2nd set of walmart specials is going strong @ 113k miles...

 

Well I disco'd all the battery cables and after testing I had one battery that only showed 10.5V despite the truck having been hooked to a charger all day yesterday. Pulled that one and exchanged it for a new one and VROOOOM... back to life.

Now I just need to set some time aside for diagnostics on all the circuits to see what is killing these things.

Could be the foglights that were installed after the sale. Or maybe the Edge computer. Perhaps the Viper alarm system? Trailer wiring? Oh the fun of electrical diagnostics

Thanks for the advice... hopefully it will start in a couple days. That is the first test.

 

I hate to jump in here late, but you may want to consider getting a second new battery. there is, in my limited view, nothing worst that battery issues. the two batteries work together and the weaker of the two, as you found, dictate the power. just a thought, good luck!