Here is the progression of my troubles and attempted fixes:

1 week ago: Car wouldn't start. A friend hooked up jumper cables and it started.
Next day: Car struggled to start but she got going nonetheless. Went and tested my battery at auto parts store - they said it was bad - I replaced it.
Next couple of days: Car continued to struggle to start but would start nonetheless.
3 days after new battery: Car wouldn't start. Tried to jump it, but still wouldn't start. Would not even try to turn over while hooked up to jumper cables - just 1 single click. All electronics worked fine though, including head lights and brights. Voltage meter looked good.
Next day: Removed the starter and tested it at advance auto. Passed all tests except for Amp Draw.
Next day: Replaced copper solenoid contacts in starter. Took it to three different auto parts stores and it passed at all three. Put starter back in and tried to start the car. Still only getting 1 click and not turning over.

My best guess is that power is getting to the starter via the small ignition wire, which allows the starter to 'click' (I believe that is the plunger connecting with the copper contacts) but is not getting from the battery to the starter via the starter wire. Probably going to purchase an Ohm meter today and see if there is current at the starter wire where it connects to the starter. If this is the case, I'm in over my head to know how much there should be, and where the electrical fault might be. Perhaps the starter relay/fuse box? I'm having trouble figuring this part of the car out using the IS repair manual.

Any help/thoughts/suggestions with all of this would be much appreciated.

Taylor

p.s. I'm sure folks are familiar/have the manual, but attached is a map from the repair manual of the starter assembly for reference.

i would purchase a new denso starter and install it. If it does the same thing return it, but test the power with a multimeter its a hotwire so it will always have a 12v

Ok cool, thanks for the heads up on which meter to purchase and what even to look for. Makes sense. That also a good idea on the starter.

Sounds to me like you have a problem with connections to the battery and starter. Bad ground....bad contacts...corrosion, etc. THAT would be my diagnosis. .

That's what I was thinking at this point too, but I just tested the starter wire and the top bolt while the starter was removed. I used a klein multimeter, touching the red lead to the starter wire and the black lead to the top bolt that holds the starter in. It measured 10v. I assume I did this right, and that 10v should be enough to at least get the starter to attempt to turn over, right?

At auto zone right now buying a new starter to try that route. Will be trying that out later tonight.

Thanks so much for your input, I really appreciate it.

Auto zone was the fastest turnaround so I picked up a duralast starter yesterday. Installed it today. When we tried to start it we discovered the car battery was dead. We didn't leave any lights on or anything - a bit strange. Hooked up jumper cables, tried to start, no turnover just 1 click. Tested starter wire with multimeter- it's reading 12.35 - so I'm totally lost. Didn't quite figure out how to test ignition wire. But I think I'm going to give up on the idea of fixing it myself. Maybe it is a bad ground but I don't know why that would be the case and how to fix it.

Thanks again for the input yall. Cheers

Yeah... I knew it wasn't the starter. As I said earlier, I'd be surprised if it wasn't a bad lead somewhere.

On edit. Keep in mind that even if the ends of the leads are good, the wire inside the insulation could still be corroded. As well, you're reading of 10 volts is weak. Also, current draw is important, and with any corrosion, that current draw will increase.

The ground wire is pretty easy to trace. It goes from the battery down, under the tray, attaches at the body, then continues down and attaches to a bracket at the bottom of the block under the header near the engine mount. Any corrosion on that part of the wire could cause voltage at the starter to read lower than at the battery.

Also, this is the primary ground wire. There's 2 other secondary wires that are about 10 gauge in diameter. One goes from the firewall to the head, right above the heater hoses. The other wire connects the transmission to the chassis and it's sorta in the trans tunnel.