Buy yourself a $10 remote starter, jump the starter relay (both power wire sides) with it and see if it spins the starter. If it does then you have the common remote (ign to relay) wire burn out. Its not sending enough volts to fully engage the relay.
Or if you have a volt meter, have someone try to start it with the volt meter + on the remote wire (should have 12 volts).
If you replaced the starter switch (lower colum) and did not align it right, then it would not engage the rod fully for it to start (had this issue on my 91). I fixed the starter switch issue (after going threw 4 of them) with a button switch to by pass the tumbler, key on then button start. As I could not get it to stay aligned no matter what I did (even used lock tight on the bolts, still would not stay put). Even made some brackets to help keep it ligned up with where it should be and still after the 3rd or 4th start, that was it for that one.
If you replaced the starter relay (on fire wall) did you make sure it had solid ground? If not run a secondary ground from one of the mounting bolts to the Neg. Terminal to ensure solid ground. The ground threw the bolts to the fender well are not the greatest. And will rot out very easy. Even if you use Grade 8's.
Check battery Terminal connections to make sure they are CLEAN and SOLID/TIGHT. A loose terminal can also give the same effect.
If the starter would not disengage, you are supper lucky it did not catch fire and burn up on you. I would have to say with that issue, you might have burnt out the remote wire (its only a 12 gage wire) or damaged it to the point it is not sending enough volts to the relay to engage it. And I would be counting my lucky stars that it did not burn up. Glad that your MOM made it home safely with that happening.
