Alright guys, here's the deal.

I installed a Pioneer DEH-P5000UB into my 2003 Eclipse Spyder GS with the Infinity OEM system (the one with the stock amp installed under the passenger seat). I used a harness connector from circuit city, and bought the DIN cable adapter from a local car audio vendor. The deck made my stock speakers sounds beautiful, but for some reason when i start powering my subs (by screwing in the ground and power cables), there is no sound anywhere in the car. There is sound, however, when the subs aren't being powered/aren't in the car.

I'm running a pair of 10in MTX RoadThunders, and I don't recall the numbers on the RoadThunder amp they are paired with, if that is necessary i will get it.

I was just wondering if I needed to bypass the stock amp in order to get my subs to work, or if it was some sort of an issue with the RCA cables being pinched off and grounded somewhere, or what.

Thank you!

The stock amp on the car is not enough to run the subs. it can handle the stock speakers, but nothing else. You should get a new amp for the car. they're cheap at the flea market, or you could spend some money and get a nice one. The factory amp was never meant to power/run anything but the stock speakers.

Exactly.

Heres what i would suggest. Unbolt the passenger seat and see if there is room for a new amp (im going to do this so i can let you know). If so you can get a harness to attach the factory wires to the new amp, then run the wires for your sub to the amp. If not you have to find another place to the amp and run all new wires (which could involve replacing the speakers).

OR you could just get an amp for the subs and run the wires to that

It all depends on your technicall knowhow and bankroll

The easiest way is just buy a separate amplifier and run the the subs of of it. Why go messing around with all that extra stuff when you can do it the right way and it's easier as well.

Well im actually replacing all the speakers. if your just adding subs then just add an amp for the subs.

If you're doing speakers, use an integration harness from your new headunit to your factory amp so that it will power your new speakers. And then you can still use an aftermarket amp to power your subs if you decide to get them.

^this my friends, is called truth^

well i already have a separate amp for the subs, and when i power the subs, there is no sound.

ground wire is bad

i never even thought of that! is there any particular way to test that, or basically since it doesn't work that's the test? haha.

get a unpainted bolt and washer, put the wire between the bolt head and washer, see if it works.

Thats the test.

Fact: Electricity needs a path to the ground (or some type of grounding) to do anything

You're running the power directly from the battery right? I'm not trying to insult you or anything, sometimes people just make mistakes.

yes, i'm running power directly from the battery.
the ground cable is still grounded by an unpainted bolt to the metal in the trunk of the car
however i haven't had a chance to get a new ground cable to test and see if the one i have is crap.

Did you get the amp new or did you get it used? are the speakers new or used? could the amp or speakers be dead possibly?

When you say it doesnt work, does the sound in the rest of the car work and just not the subs?

I think he means, there is no sound anywhere in the car, speakers, or subs.