When I bought my '97 EX Civic Sedan it had an after market Pioneer HU already installed. The front speakers did not work then and the clock on the HU did not work either. I could not set the clock as instructed in the HU manual. I attributed the speaker problem to the HU being bad because of the clock issue. I have recently replaced the HU with a brand new one, and the front speakers still do not work (no sound at all, not even a hum). I do not have any tools to test for signal to the front speakers. My solution is to run new wire to the speakers and see if that fixes it. I have the factory paper speakers still. The back work just fine. Does anyone have any ideas as to what could be the issue? Could the wiring harness be the issue? I also replaced the HU adapter harness with the correct one. The one that was on it when I bought it worked but had extra pigtails.

 

Plug rear speakers in to confirm the fronts are not dead.

You can remove the front speakers from the doors, bring it into the vehicle and run wire to it. No need wasting your time running new wires into the doors if that is not the problem.

The tool used for testing this sort of stuff is cheap. Usually less than $10.

 

It's pretty common for factory speakers to go completely dead. Check the speaker for continuity, if open circuit the speaker is bad. If it is normal ( a couple ohms of resistance), plug in the speakers then test the car wiring by measuring ohms at the head unit end of the wires.

Speaker wires shorted to ground will partly or completely shut down the head unit amplifiers. Make sure all speaker wire have no continuity to ground.

These tests will require buying a simple volt ohm meter as cvcrcr said.

 

I did the quick test of plugging in the front speakers to the rear and they worked. They were really quiet compared to the 6x9's and a bit fuzzy. I do plan on replacing them. I believe they are on their way out.