88 Sentra wont start

My little sis bought an 88 Sentra a few months ago and weve had nothing but trouble with it.

Weve replaced the battery, terminals, starter and alternator over the past few months.

Starting this past weekend, it wont start any more. Everything powers up, but when I turn the key to on, just a click.

We think it is the ignition switch. What are your thoughts?

I know you said you replaced the battery but it sounds like it needs a jump. Did you try that yet?

Its worked in the past but jumping has not been effective as of late. The battery still has a good charge, but the starter is iffy. It tested bad twice at Autozone but tested good at Checker when I went to return it....

Engine you said just clicks? I know you put a starter in , double check your grounds. I would start there first

Its been starting all the time today. I went ahead and replaced the battery cable, as that was suggested...