I have a 2001 SR5, so that's my focus, but I got to wondering about Toyota's system for naming parts, and how consistent it is over time.

I'm currently trying to learn/understand the electrical system in my car (stemming from a faulty security / alarm system) and in the process, have dismantled much of my vehicle's interior, examining wires and connectors etc. It occurs to me that it sure would be handy if the connectors were labeled somehow, and since I've got access now, why not label them myself? I'm thinking a neon color paint pen. It would make things much easier for the next round. Anyone done this?

And how "portable" will those labels be, anyway? Not that it matters too much (exceot maybe for the future salvager who dismantles my old car in a junk yard).

For example, in my 2001, the "Engine Hood Courtesy SW" (90980-11273) is called "E13". Is this same part called "E13" in all other year models?

Also, does anyone have a pic of this part, in place, on a 3rd gen? I cannot seem to find mine. Do I need to remove the radiator to get access to it? Thanks in advance if anyone knows.

But my main question is about Toyota's consistency over time in their naming of things.

(Also btw, does anyone have the wiring manual for 2001? I have the 2002 version.) Appreciate it if so!