It's a common issue in modern Automotive wiring. the installation has soybean oil mixed in with it and mice love to chew on it
Excellent info, thank you!The connector itself should have 5 digits printed on it. In Toyotaland, the part number will be 90980-xxxxx, where the last part is the 5 digits on your current one. Toyota may also sell a connector pigtail with short lengths of wires already in it. That's probably the best option, since it looks like you need some additional length to make good splices.
It's also not so hard to replace the terminals. With the Toyota part number (and probably your photo), contact Ballenger Motorsports and they'll get you sorted with the proper terminals and insulators, and you should be able to restore it back to new. You'll need a terminal release tool. You'd still end up having to splice wires somewhere though, so the Toyota connector with pigtail is likely your best option.