My old injector wiring harness was shot, so I got another one. The first issue is that the old one and the new one aren't the same.

Old harness

The new harness has a three pin connector and a ring terminal that the old one didn't have. I'm guessing the ring terminal is meant to be a ground and I can put it wherever is convenient. Where does the three pin go, or is it not used on my car? I have SN 143000 with a build date of 6/87.
Next, I found two other connectors that I don't remember unplugging and can't figure out where they go.

One pin white with a blue trace
As you can see, this one is in the same wiring harness that goes to the throttle capstan.

White with a trace too faded to tell what color it's supposed to be.
This one comes off the ignition amp.
Are those two white wires supposed to be connected to each other? My tachometer hasn't worked in years. Is this why?

 

To partially answer my own question, I contacted Welsh Enterprises, from whom I bought the injector wiring harness. They got back to me with a voicemail saying that on an '88, I can just leave the extra connectors unconnected. I taped over them and will try installing them today.

 

I got the harness in. It runs better than it did. However, it's hard to start, has a rough idle, lacks power, and the lightning bolt warning light is on. At this point I'm calling it a tomorrow problem.