you should:
1)update your signature to say what truck you have
2) say what you are working on
I went back and checked your other posts so gonna say you are working on your 87 4Runner. Crap changes periodically and this section covers 11 years worth of trucks so stating what you are working on helps others help you
does that wire have power?
Test light or DMM will tell you
if its got power tape it off to prevent a short if you don't need it
might google 87 4runner stereo wiring but gonover is probably correct, check back up lights