With a lil help from my friends....

[Batman27976]

OK. I need the electrical experts on this one.

I have an '04 ST 4WD XLT Premium and my battery keeps dying after about three days of sitting. New battery AND alternator which is charging perfectly. I took it to the dealer and they did a complete test and told me there was nothing wrong and couldn't find any source of battery drain.

I disconnected both battery connections, both plugs and the terminal on the alternator to isolate the harness. I read resistance from the alternator terminal wire to the positive lead and, of course, it read zero. I read from the same alternator wire to the negative battery terminal on the harness and it reads about 250 ohms. I don't have the schematics but I'm thinking it should read open with the harness disconnected. Am I wrong?

 

[grimmolate]

I'll be trying to track down the same problem on my 03 this weekend. Here is the diagram for the charging system. From the 03 manual but probably the same for yours.

Seems like you could be right, may have a short. I'm assuming the dealer checked for parasitic draw when you took it in?

 

[Batman27976]

Thanks for the response Grim.
Yup. I was told they did a draw test and didn't find anything. I guess the next step is to disconnect the harness completely, including the starter and go pin to pin. That harness kind of snakes through the engine so it could be a bit of a pain to get out and back in.

 

[grimmolate]

Good luck, I hope you get it figured out. Post up what you find, and if you want anymore diagrams, let me know.

I'm hoping my issue just has to due with where the previous owner put in the after market radio or trailer hookups. Much more interesting things I'd rather be doing to the truck than tracking down electrical issues.