newbie with radio problem on 88 cherokee

I just bought an 88 jeep cherokee. It didn't have a radio installed,(the seller said it had been stolen). He gave me a pioneer stereo with a cd player. I bought an adapter, and wired it up. The original speakers aren't functioning, but a small pair I rounded up, are working. Unfortunately, even on the highest volume of the receiver, the output is almost at a whisper. What should I be troubleshooting, or looking at. I'm pretty new at this, any help or insight would be greatly appreciated. It'd really be nice to be able to listen to tunes on the way to work.
Melissa

well start by checking the fade on the stereo.
Meaning the left and right and the front and back volume controls.
Make sure that they are set at zero. This will put the volume evenly to all speakers.
You could still have some bad speakers.
If the stereo was stolen, more than anything they just pulled it out tearing some wires.

Hi Dominic,
Thankyou for responding to my post. :) The receiver/cd player that the previous owner had given me was a salvaged one. (he tows cars that go to a shop or junkyards) It turns out that the speakers do work, and I think the amp was blown on the unit he gave me. I installed a brand new radio and was shocked and happily surprised when sound blasted from all four speakers. I now have music!
Thanks again for your advice,
Melissa

Well thats good that everything worked out ok.

Other then that everything elso ok with your Jeep?