dnguyen211

I have a 98 Lexus ES300, GREAT CAR! However, with the radio I have an aftermarket one which is a pioneer DEH-3900MP and when I turn it on the only bass I hear is coming from my speakers and none from the sub. I have tried connecting a little speaker to the wires coming from the amp to the subwoofer in the trunk to see if there were any juice coming to them and nothing. I am using the wiring harness for it and the one for the car which has 4 RCA plugs for the 4 speakers. On the back of the reciever there are 6 plugs 4 for speakers and two for the subwoofer which i am assuming is for the amp. I do not know what the problem is but I need help ASAP!

93stickes

Unfortunately the stock subwoofer will not work with the aftermarket stereo. The stock amp does not use the pre amps you see on the back of the stereo. You would need an aftermarket amp, and I would replace the subwoofer too because it will sound better and be way easier to hook up. You don't need anything big, a 10 or a 12 should be fine.

Mythotical

Actually I was able to use the after market wiring harness with the four RCA connectors hooked up to the four channels on the back of the HU not the sub pair, just the four channels. Then I did the amp bypass wiring at the amp behind the glove box by using the high level outputs of the HU for all of the channels accept I left the sub hooked up. So with the RCA hooked up and the speakers hooked directly to the HU and not to the amp I am able to use the factory sub and the factory amp only for the sub. Hope this helps.