Still testing everything, don't shoot the parts cannon yet. This should help identify who should have power when:

 

Can I blame that on missing neurons from old age? That's becoming a handy excuse in cases like this.

 

I don't believe a 1990 actually has a stock ground there and only had the ground strap from the back of the block to the firewall (also a common failure point). I usually like to add right at the battery, though. Using the picture Dave posted of the starter solenoid on the passenger fender, you can see the middle terminal that you can try jumping to battery + to see if it cranks. That'll definitely rule out a bad starter.

 

The starter is new. I'm gonna check the starter relay and ignition switch tomorrow.

 

Ignition switch and starter relay was replaced and still no luck. ☹

 

Do you have a multimeter?

That means don't replace things unless they need replacing.

 

yes I own a meter

 

Ground your meter to the battery.
At the starter relay see how many volts you got at battery terminal and how much it drops at start.
Measure the ohms of the ground wire from beginning to end. If you can't do that in it's entirety put a new wire from ground to battery.
Jump the battery terminal to the solenoid terminal (briefly!)
Ground your meter to the battery. Measure ohms (or volts, doesn't matter) of the ignition terminal at off and at start (well, just start really). If that's open run a new wire from ignition to ignition switch.
IDK what fuel ballast is supposed to be doing. Need someone to chime in.