Ally.o

Hi there.. would really appreciate some advice, few weeks ago alternator went, few weeks after, car occasionally cuts out of power, i'l open fuse an relay box under hood, press em all down, car starts. This is now more regular & few days ago the dash lights & starter motor, all working, but car didn't want to stay on. last night, no electric to dash or starter motor, so car wouldn't start. Elec seats, door lights still worked. It's like a loose connection somewhere..