I have a 2001 Ram 2500 with a 5.7. ran fine the other day, now today i tried to start it and the battery was dead. found out the brake lights were stuck on. fixed it. charged the battery, now it will start and run but not idle. doesn't matter if it is in gear or nuetral, park. any ideas? I've never had a problem with it before.

 

Welcome to DF!

If its a 2001, you don't have the 5.7L HEMI unless it was a custom swap. Do you mean the 5.9L diesel, or the 5.9L gas V8? The answer to that question will help us help you.

And just for future reference:
https://dodgeforum.com/forum/dodge-r...s-section.html

 

It might take a few starts for the IAC to relearn after the battery went dead. Assuming of course it's a gas 5.9.