UPDATE: I stopped by another parts house and had them test the battery. It showed a bad cell and zoro cranking amps. I took the printout to OR where the battery wast under warranty, they gave me a new one and the truck starts fine now. Beats me how the OR 10 minute test showed that battery to be good.


My '04 5.3 has 100K+ miles on it and a week ago I got in it to leave a jobsite and it didn't want to turn over. I had left the doors open for a couple hours and figured I ran down the battery. I put cables on it and it started but cranked very slow at first then started. The computer had reset so it didn't want to idle until I drove it a mile or two. After that every time I started it it barely turned over then started. I finally got time to have the battery tested and it tested good. I then removed the starter but it tests good. I still thought it was the battery so I hooked up another battery to my cable and it still barely cranks before it starts. The alternator is reading 14v at the dash guage so I'm stumped.

One more thing is I reset the clock on the radio then the next time I start I have to reset the clock again. I assume the start pulls the battery down so much that the PCM loses power?

I really appreciate your help with this.
Steve

 

It sounds like someone didn't want to replace the battery under warranty. There's hardly any way the battery could have tested good with a bad cell.
A quick test I do is to put a volt meter across the battery with no load. It should read around 13V, maybe a little more. When you hit the starter, it should not drop to less than 9v. If it does, the battery is not fully charged or may be bad. With a dead cell, the no load voltage would be less than 11v and would drop way down on full load. I think the first person that tested the battery didn't do something right. Sounds like you have it fixed now. Thanks for the update.