Yes, actually it did come with the phone. I'll check that out. Thanks, that helped.
For what its worth, I have a 93 ls and the exact same problem. For me it wasnt the speaker/s at all. It might have to do with the phone amp but I removed my phone and it didnt help. I believe it is a break/bad connection under the seat or at the driver kick panel. I fixed it by running a new piece of cable to the speaker conn behind the seatbelt cover on the driver side, under the door sill cover, behind the kick panel and up to the stereo. I just used a cheap speaker and wire to find the correct output from the stereo and soldered aand sealed all connects. Its a pretty easy job and the speaker has been working perfectly for 6 months. Hope this helps.