no sound

For my 1991 240sx im getting sound out of one speaker. I'm tryint to install my jvc cd player. when had it hooked up sound came out of one speaker. I double checked the wiring to the cd player and its good. I thought my other speakers might be blown or something so i took them out and tested them. they worked but when i checked them by hooking them up directly to the cd player the speaker that worked before didnt work. Y is sound coming out of only one speaker?

The wiring between the headunit and the speaker could be cut or broken, have you tried connecting the speakers to the headunit directly, not using the stock wiring but just doing a temp job right there in the front seat?

yeah and when i did that the speaker that worked a min ago stopped working. Only the speaker i connected directly worked. i can never get more then one to work at a time