Good location for ground wire?

[shaftwagon]

I just installed an alpine 5-channel amp in my MS3 sport and have a nasty alternator whine. I initially tried grounding the amp to one of the bolts underneath the frame of the seat- but I guess that's not a good spot.

I searched but couldn't find any suggestions of grounding locations in the car. Can anyone suggest a tried and true one in Mazda3/MS3? Thanks much.

 

[bgibb68]

you can use the seat bolt but you need to hit it with steel wool or something to take the paint off so there is metal to metal contact

 

[Rotus8]

There are good ground spots on the front door posts just below the dash. Pop of the kick panel and they are obvious.

 

[MikeHTally]

Direct to the battery with a 4 ga. wire? That whine may not be so easy to fix, though. I used to do this for a living. Sometimes you get lucky and the first things you try take care of it. Other times it can take hours. Make sure your inputs are snug.

 

[240ka]

I just installed an alpine 5-channel amp in my MS3 sport and have a nasty alternator whine. I initially tried grounding the amp to one of the bolts underneath the frame of the seat- but I guess that's not a good spot.

I searched but couldn't find any suggestions of grounding locations in the car. Can anyone suggest a tried and true one in Mazda3/MS3? Thanks much.

you didnt run the speaker rcas on the same side of the car along with the power cables did you? where is your amp located, mine are in my trunk and they are grounded to two of the bolts where the spare is holding down the plastic piece that the tow hook and tire iron sits in.

 

[bgibb68]

240ka is right about keeping the rcas away from the power cables....try to keep them on opposite sides of the car untill they hook to the amp

 

[shaftwagon]

I ran a 8 ga power cable through the grommet behind the glove compartment as suggested in the boards (super easy!) and it runs under the passenger side rail. The inputs/outputs are in the center of the car so it shouldn't be an issue. I had this system in another car and there was no whine, so I figure it's a poor grounding issue. I did find the bolts under the kick panel. Thanks! I'll need to buy more wire to make the distance though.

Here's the weird thing- the whine COMPLETELY dissapears when I plug my IPOD directly into my amp (via RCA connection). The amp accepts speaker level inputs, so that frees up the RCA's so that I can plug in my IPOD. Does that sound like a grounding issue?

 

[Retrobmx63]

Have you tried a ground loop isolator to get rid of the alternator whine?

They're cheap and work great.