DYI speaker amp fail, need some wisdom!

[Jeffl]

ok so I've been installing my system in my "new" 2006 dodge stratus over the last week or so here and there. Anyways finally got around to hooking up the rear 6x9 to my 4 channel amp and i get a nice static / hiss from them while the car is running, plus a alternator whine thats seprate as well. I have my power wire running down the driver side of the car and my rca's down the other side of the car alone with some speaker wire which i must note are NOT hooked up to anything. gounded the amp to a whole i found on the top of the baffle where the 6x9 sit, sanded down some of the paint and stuck a nut a bolt and a washer for my ground.

Also my current 4 channel amp http://www.sonicelectronix.com/item_22573_Kenwood-KAC-8405.html doesnt give off any voltage, when i use my dmm on any of the channels with the rca's plugged in it just reads 0.00 or flashes -0.00 but the amp still produces sounds out of the speaker, just very quite even with the gain set to max and master volume of the head unit set to 3/4 max. any idea of what this is? fried amp or what. this could explain the problem up front since this is the amp to the 6x9.

[Jessica]

Maybe check you HPF and make sure it's not on and cranked all the way up. Then check the rca's. It sounds more like a bad rca cable than anything.

[Noel989]

When you say max on the gain do you mean all the way up or max that you already set gains?

Like strangeduck said check RCAs not just from the amp but from the deck to

Do you have anything in between you stereo and amp like an eq?

[rockFord_Expedition]

By the way it sounds, your ground is not too solid. Got a pic of it?

[Jessica]

Also, that ground may not be the greatest, but for no more current than that amp draw it really should work. If replacing the rca's doesn't fix the issue, you could try moving that ground to the strut tower. What head unit are you using?

[Jeffl]

using a JVC bt-r820bt says to have 2.5v outs but even at max volume they max out at 2 volts... but im going to try and change the rca's next time i go out.

[Jeffl]

UPDATE: so I went and tried to switch the rca's and it didnt work I unplugged them and the noise was still there so I believe ist a grounding issue. i"m going to change the ground location tomorrow. Also will a too long of a ground wire make that noise as well? I have 2 amps hooked up sub and 4 channel so i'd guess my ground total is about 4.5 feet.

[rockFord_Expedition]

Shorter is better, but not at the expense of a good location.

[conceptM]

The plates where your rear speakers sit in tend to be spot welded to the frame. Resulting in a bad ground. I mostly use the bolts for the belts as these are close to the amps & tend to be a good groundlocation. My reasoning is they are pretty sturdy on chassis for obvious safety reasons.

[White Lightning]

Also, Keep in mind that an amplifier will make power even if the gains are turned all the way dowm ...

I run my amps with zero gain ...