When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
In case your problem hasn't been solved, I had similar issues in my older SC. My car kept dying when I was below 1k rpm, regardless if I fully charged the battery.
Turns out the PS pump was leaking fluid and the alternator is located directly under it, causing the alternator to go bad. I had the PS pump sealed up and got a new alternator and didn't have problems after that. My friend told me after the fact that if that is the case, the alternator can just be cleaned using brake fluid cleaner and a replacement is not necessary.