toyota corolla 1990

Wiring information isn't showing an amplifier in that car, double check your wiring, may have loose connection somewhere, if it was working and cut off, and you checked speaker outs with a test speaker, then thats what I am led to believe, or possibly a speaker wire grounding out down the line somewhere.

Try connecting your speakers one at a time, see if any of them will work. If they work and quit when you connect one in particular, then it is more than likely grounding somewhere in the line, maybe even the speaker itself, if in fact you have changed them out.

If you have changed them out and you find that is the problem, then also check the terminals on the speakers, make sure they aren't anywhere close to touching any metal on the door/inside.

Hope this is helpful.