I have a 2001 Ford Focus ZX3 and the car has started dying on me. Sometimes it will crank and sometimes it won't. It will not cut off while I am driving down the road but it will die on my when I stop at a light or something.
If you get out and wiggle the wires to the battery sometimes it will crank back up and sometimes it won't. It will always start if I pop the clutch. I have had the battery tested and it shows to be fine. My husband also replaced all the battery cables because the red cable was caroded and crisp.
When I stop and the car don't die on me I watch the rpms jump between 1200 rpms and 900 rpms.
I know that my husband has had the car running and unhooked the battery hook up from the altinator and the car did not die so he thinks the altinator is still good.