1993 Chevy Corsica low fluid level light won't go out

Had a rad hose replaced, filled up the reservoir again and the low fluid level light stays on. Temperature gauge reads normal, fluid pressure is built up in the hose okay. The car is now stalling and when it is running it is lurching as if it is sputtering, don't know if this is altogether or not. Can you please give me an answer as to why it is doing this and what I should do! Thank you
Heather vanHoof