No engine whine/noise before new head unit + expansion module install. There was an amp and sub already installed with no noise issues. Amp was grounded near the rear of the vehicle.

I ran the ground for expansion module to the battery negative terminal. Now I hear some engine whine. Is this likely a ground loop, and if so, should I move the expansion ground to share the same ground as the amp near the rear?

Thanks,
First Poster

 

what do you mean by expansion module? Also, which head unit/vehicle is it?

 

Didn't think that was relevant. Its a panasonic cq-c7113u with a CY-EM100U expansion in a '06 Civic. The expansion draws power and has 2 ground wires. Installation instructions don't specify anything about them. One is really short, other same length as 12v cable, so I have the longer going to battery negative.

 

Ground both to the chassis in different spots. is the sub and amp hooked up with the line level converter? or ae the rcas direct to the deck now?

 

RCA to deck now, was line converter. Can I ask why different spots on chassis?

 

All grounds traditionally should be as short as possible, and in all different areas to the chassis to minimize noise. It's also less expensive to move some grounds around before trying an isolator. A ground loop isolator can also degrade the sound quality.