If you're bored before friday, you can try cleaning the connection points at the positive battery terminal (make sure it's actually clamping the post), main relay, the terminals attached to the main fuse block. If you jump the terminals of the starter with something like a screwdriver, will it spin?

 

All connections are spotless, I'm meticulous about that.

Never been a fan of jumping terminals like that...something about that much amperage through a screwdriver in my hand just doesn't sit well with me. I've been electrocuted too many times, I don't push my luck intentionally.

I did not because I don't have a blue plug. I have a factory anti-theft that is hidden somewhere under the dash. Saying "under the dash" or "look in the FSM" is zero help; someone should make a help website called rx7diagnostics.com and on the main page just put "LOOK IN YOUR FSM", it'd be about as helpful.

I don't think that's my issue though; reason being when the starter does spin, it sounds labored like a bad battery. That is not indicative of a bad relay.

I put in a new battery with the same results. Yes, I cleaned/checked all connections. I put my regular battery in my other car and that car started just fine. This tells me the battery and connections were fine to begin with and not the culprit, so I move on to the starter itself; $20 for a solenoid? $20 for brushes? $70 for a new starter unit (motor/brushes/solenoid)? I just bought a new unit to eliminate the entire thing as a cause.

I'll put the car on ramps today after work today (I only get a few hours of light after work) and fiddle with the starter connections and see what I can get to happen.

 

Jumped the contacts, starter spun fine.

No amount of wire bypassing or jumping could trip the solenoid.

Replaced entire unit (since I had it, might as well) and everything's perfect again.