do I need to disconnect the battry cable or can I leave the battry cable connected when charging the battry?

You can leave them connected.

If you get him going, take him to a popular auto parts store and have the battery and charging system tested. This is normally a free service.

This might help you too, before you buy anything!

https://www.2carpros.com/questions/2001-dodge-neon-milage-just-want-put-fliuds-their-locations

Let us know how it goes!

The Medic

I charge the battry 2 hours the engine is cranking now I connected a volt meter to the battry and it show 14 volts is that a good charging volt? I havn't check the battry yet.

Yes!

All seems good as far as home testing!

Get it fully/ thoroughly checked at an auto parts store

The Medic