Sit for a Week, Batteries dead. Whats going on?

[Suprman]

so this has happened twice now, first time i thought it was the trailer drawing power, but this time the trailer wasn't hooked up.

last time i got the batteries tested and they were fine after recharged. whats going on? truck will go 3000 miles fine and then after it sits a week, it loses all charge?

also jump starting this truck is a pain, my jump box won't do it, they only thing i found was another f350 to jump it last time. Anyone recommend a good jump box as well as the solution to this problem?

[smuesse]

Mine was doing the same thing. I had the batterys tested by ford and by another shop and they tested fine. It got down to where if i let it set for 1 day they would run down. Finally i just went and bought two brand new interstates and its been great ever since.

[drz400smoto]

Originally Posted by smuesse

Mine was doing the same thing. I had the batterys tested by ford and by another shop and they tested fine. It got down to where if i let it set for 1 day they would run down. Finally i just went and bought two brand new interstates and its been great ever since.

How is it that they tested them and said they were good but they really weren't? I have a feeling I mite have same problem.

To OP
Im having similar problems with my truck, it used to be every other day it wouldn't start in the morning, but after I jumped it and drove to class it had enough to start to get back home. Now it seems like every day it needs to be jumped. I also had the batteries tested at checkers where I bought them and they put them in there machine and charged them and said they were fine. My alternator was only putting out 12v so I ended up replacing that but still have the same problems. I disconnected my stereo equipment and alarm from my battery today to see if thats drawing it down.

[smuesse]

I dont know how they tested good. I asked them what they did and he said they discarged them and then charged them back up, then tested.

[drz400smoto]

Yea Im wondering if its the same case with my batteries

[Dave]

Do you have any accessories hooked up that stay on overnight. Fuzzbuster, GPS or something like that?

[trucktractorman]

You wont find a jump box stout enough to turn over a diesel. At least Ive never seen or heard of one. Get you a couple of new motorcraft batteries. Those work the best.

[Austin G]

We have a jump box we used to turn over a '97 powerstroke, but only 1 battery was dead.

[Sinac]

Originally Posted by trucktractorman

You wont find a jump box stout enough to turn over a diesel. At least Ive never seen or heard of one. Get you a couple of new motorcraft batteries. Those work the best.

I've got one... I start CAT C9 and C-9s and Cummins QSLs with it almost on a daily basis. You get what you pay for, especially when it comes to tools.


Also, it starts them being 100% dead. I mean nothing is on, no lights or anything.

[drz400smoto]

Originally Posted by Dave

Do you have any accessories hooked up that stay on overnight. Fuzzbuster, GPS or something like that?

I don't have anything like that hooked up, yesterday I disconnected my amp power wire, alarm power, and head unit power to see if they were draining the batteries and it still needed to be jumped. It has enough power to start and about 4 hours later it needed a jump.
Whats the best way to test for a drain and find it?
I disconnected one battery completely then took one cable off the other and put a light tester in between the open terminal and the cable and it lit up, so Im pretty sure there is something draining on them.