Aftermarket stereo install and one speaker stopped working?

I finished installing a pioneer head unit into my 1998 honda civic but when I was done only 3 out of 4 speakers were working. My front passenger speaker was not working, i pulled out the speaker to check those connections and they were fine. The speaker was working before the install. Should I just put new speakers in?

If the speaker was working BEFORE you installed the stereo, and now it isn't, what makes you think the speaker is bad? Check your work. Could be a bad stereo unit. Did you think of that?

I was just lost and wan't sure what else it could be besides something wrong with the speaker. The head unit has been in the last 3 cars with me working without a problem.

Plug a known good speaker on the wire where you have trouble and see if it works. Maybe the wire itself is bad- disconnected at the other end, or broken inside its insulation somewhere. If the other speaker works in that wire then the wire is good, if not, pull a new wire into place and connect it up.