3rd Gen RX7.

Car was having problems starting but after a few tries it would always turn over eventually. Yesterday I turned the key and same problem except this time the starter didn't click. Upon inspection I can see the rubber cap on top of the alternator that was very pliable is now very hard and cracking and farther down the line the insulation is melted to the wire and other parts are exposed. Obviously I would want to replace this whole section along with the clip on the alternator because there is wear there also, but I do not know what to ask Ray for when I want the part. The manual refers to it as "Connector" and "Terminal B". Thanks for the help.

 

Both of the pieces you mentioned are going to be part of one of the car's main harnesses. It's is very doubtful that Mazda will sell these pieces alone, so you'd probably be looking at buying an entire harness. That'll get expensive in a hurry.

For what it's worth, the plug you mentioned goes to the L and S terminals of the alternator. The S terminal is fused power for the voltage regulator, and the L terminal runs to the dash. Another name for the B terminal is "B post", and it connects to the positive battery post. It sounds like you're describing the ring terminal and rubber cover. You'll probably be better off finding a good used harness in the classified section, then either splicing in the pieces you need to replace, or swapping it out entirely.