Last week, I put the Kenwood radio in my 2004. I wired it to the factory plug via the front speaker wire out from the radio and it worked fine. I could not tell if the subs were doing anything at all, so I figured I'd try the method that is mentioned here
https://www.crossfireforum.org/forum...tml#post693937
I ran the front rca out to the factory harness, and ran the subwoofer rca out to the sires split off at the rear amp. I also tested as I cut the factory wires that the door speakers still worked, confirming that the correct wires were being cut.
I did not appear to get any sound from the subs, so I temporarily moved the sub rca jacks to the front output on the radio (assuming that is effectively how the car was wired) hoping to only hear deep bass from the subs, and obviously nothing from the doors. All I got was a faint crackle from the left sub behind the driver's seat.
Also, as has been mentioned many times, the volume is pretty low on some songs, and most, I can run the radio at it highest setting of 35 and it still isn't too loud. When I had the speaker outs hooked up, it was too high of an output, and I used the audio settings in the Kenwood, and reduced the volume to the lowest setting and it was about perfect, I could turn it to he max on some songs, and it was very loud, but still clear. I highly suggest that for anyone wiring it that way.


SO, to sum up, how do I test factory subwoofers? If I could get the damned pins out of the jacks, I would switch some wiring and force audio to them. The car just turned 6,000 miles, and has been sitting garaged for all its life, could the subs be shot? I don't think it is that because they are silent, not crappy and weak.
I was hoping to use the High Pass and Sub filters in the radio instead of wiring in a filter capacitor. But due to the limited volume ( I assume because of the 2.5V output) I will be switching back to the speaker outs.