This should be pretty straight forward.
What you will probably need to do is replace both front speakers, after market is ok, so you don't need to do factory. You'll save some money.
These speakers need to be matched so you will need to remove at least one speaker to see what you need.
But, before you go out and buy anything check out the wiring on the back of the speaker you're having trouble with.
The connectors on the back are labeled + and -. This is so you hook up the correct wire to each point. When you look it over see what it tells you about the quality you see. Check out the diaphram to see it's not broken. On the rear make sure the wiring is sound and unbroken. Don't just look at the wires that connect to the speaker but the wires going the speaker wire connections to the speaker itself. Just remember, if it looks soft, don't touch it. Grab the hard stuff all you want.
Also, before you go buy anything, remove the stereo and look at the rear where they connect everything. The modular plug back there should contain all wiring for all speakers, only the wiring will be color coded.
Follow the path for all 4-6 sets of wires as 2 sets will go to the front doors and two sets will go to the rear. Some vehicles have an intermediate set of speakers.
Most speaker wires will run under the drivers threshold, thats the aluminum plate that protects and holds down your carpet. Unscrew it and lift it up so you can check for wiring damage.
Since your front speakers do work, you may only have a bad + or - wire connection on the driver side and MAYBE a broken harness or maybe one that is just unplugged for the back.
To learn which it is you will need to look at the back of your stereo and follow the wires.
This is kind of like a treasure hunt with the treasure being a loose or broken wire and not a speaker or a set of missing speakers, so do remove the cover from over the rear speakers to make sure they are still there.
Let me know what you findCustomerand we can go on from there.
It's just about 6:30 here so I'm going to break for dinner. Just let me know.
Thanks for using Just Answer for the help you need.