New power outlet mod + engine noise question

[chrism]

I have installed a new aftermarket amp with the OEM HU under the passenger seat. While I was doing this, I decided to buy a power outlet at PEP Boys. This is simply an aftermarket power outlet that is suppose to go under your dash, but I installed it behind the drink holders in the center of the vertical black space right below the handle where you open up the console. I hooked this up to the power lead to the amp, this way I have a power outlet that is constantly 'hot'. Installation is simple - you just drill a small hole in the center of the where you want to install the outlet. This hole will be drilled through both the removable cup holder and the inside of the center console. You then remove the cup holder and drill a 1" hole with a 1" wood bit. Drill another 1" hole in the center console. I had to take a box cutter to enlarge the hole slightly in the cupholder piece due to the way the power outlet installs. When you are done with the holes, snap the cup holder piece back in and install the power outlet in the hole and connect the power and ground wires. I am going to use this for my cell phone charger.

I am using the bolts that secure the center console as my main ground. Does anybody else use this as a ground? I just got everything hooked up today and have MAJOR engine noise. I am going speaker level (front right and left) to my EQ's speaker level inputs then RCA's out to the amp, then to new speakers (all 4). I ran 8 gauge (monster brand) from the battery to the amp and I am also powering my EQ with this. I'm using the ac switched from the blue wire behind the HU. Of course, it sounds great when the truck isn't running, but when I turn the truck on it's bad! Is there an obvious ground error? I guess I will go get a noise filter and start diagonstics with that. Any ideas?

Hope you find the power outlet mod helpful!

Chris

[Stooge]

Try grounding the amp at the negative terminal of the battery.

[nhparrot]

First check ALL your grounds. Most audio noise in vehicles is the result of bad grounds. Make sure grounds are short (less than 18") and are to chassis (not just any peice of metal) and that you have good connection to a bare metal surface.

[chrism]

The center console uses 4 screws that screw directly to the metal underside of the truck. Is this not a good enough place? I thought it looked pretty obvious and easily accessible. Maybe there is too much paint or something.

[Gilley]

Originally posted by Stooge
Try grounding the amp at the negative terminal of the battery.

No, that's too long of a ground wire. For an amplifier, the ground wire should not be more than 18 inches in length.

Chrism, it sounds like you may have a ground loop problem which can happen when different electrical items are grounded in different locations. I would recommend not connecting the power outlet to the amp at all, but if you do, ground the outlet at the same place that the amp is grounded. Also try grounding your EQ at the same place as the amp.

Did you have the noise problem before you installed the accessory outlet?

[chrism]

Yes, the noise is there regardless of the outlet. I have the power from the battery powering the amp, EQ, and outlet. I have a short ground, attached under the center console, attached to the EQ, AMP, and outlet. I'm using the ac switched from the HU to switch the amp and EQ. I'm using the gound on the amp that is right next to the main power connection, however, on the other side of the amp there is also a place for a ground that I am not using. It's a new Kenwood amp with pathetic instructions, so I don't know exactly what this ground is for. Assuming I don't need to use the other ground, where would I install a ground loop isolator in the other ground wiring?

[JnEsPappa]

My amp is grounded to one of the bolts which secure the passenger seat. I scratched off the paint where I connected the wire. Try that.

Also make sure the RCA's stay away from your main power wire. I assume the EQ and HU are both mounted "in-dash". Ground them at the same spot.

Good Luck chasing that noise monster. I got lucky with clear sound on mine.