messed up wiring, now no sound

i installed a new rear speakers today. the right one was installed good the left one my friend decided to say "oh white wire must be positive" and plug it in before i can go online and check the solblu's wire diagram.. i came back he said everything is hooked up so we turn the car on and the speakers were on for a second then silence.. no i cant seem to figure out what happend., i know he shortd the speaker buy puting the white  on positive, i went  under the hood and check fuse 23 for the radio but its in tact any advice??what can i do to fix this. i swapped new head unit and tried still no go.all of my speakers not working...but the radio is on..please need your advice.

-wil-

im sorry.. i have a 95 honda del sol s.. the stereo is aftermarket and the speakers are also both aftermarket (front are pioneers and the rear are polk audio)

i tried different speaker to check but still no sound.

check the fuse seems intact.

any other thing i can do?

I never knew you could damage a radio by hooking the speakers up backwards.   :)

I would pull the radio out and cut all 4 sets of speaker leads on the back of the radio.  I would then hook a single speaker directly to the back of the radio and see if it plays (this assumes there is no amp). 

If one of your speaker wires grounded out somehow it will cause the HU to go in to protection and not play any music.

If you disconnect all 4 sets of speaker wires from the back of the radio and you hook a single speaker up and it plays you can then hook up one channel at a time and see what channel causes the radio to quit playing.  You can then replace that speaker wire (or find and fix the problem).

Of course you could also just unplug the radio and test each speaker lead to ground.  Lots of ways to troubleshoot this one.

Another idea would be to hook the radio up directly to the battery (or a power supply) and hook a speaker directly to the radios output and see if it plays outside of the car. 

Another (and possibly the best) option would be to take it to a shop and pay a professional to do it correctly.