I had posted earlier I was having a problem with a small bit of alternator whine. I'm 99% sure it's in the RCA cables. When I unplug the RCAs the noise is gone. All I've done is cut a tapped the factory wiring at the factory amp. Using terminal blocks I converted the factory wiring to RCA cables. They aren't the best quality but they only run about 3 feet from the tap point. I know people have used the factory wiring without noise issues from what I have read. Would a twist and solder connection possibly solve my problem or do I need to run RCAs all the way to the head unit? If I do run new RCAs do I just tap into the wire behind the head unit?

Thanks

 

when you tapped at the amp, did you tap into the amp's output or input?

Are you still using the factory radio?

 

I used the inputs into amp (low level signals). I'm still using the factory HU that's why I didn't bother running all new wires.

 

are the wires that you tapped into all correct?
I didnt read the post about where to tap and I did not do this myself as I use aftermarket head units, but,
There could be a common ground type input into the amp and/or seperate inputs for mid and tweeters.
Alot of factory amps I have integrated into have had this.

You may be having a ground loop problem. You can try using a ground loop isolator on the RCA line.

Solder connection would be best, but is not likely to be causing your problem.

 

I used the wire diagram I found on here. Everything works great except for the slight whine. I plan on upgrading to a better HU but not for a while.

Are you suggesting I ground the factory ground wire that was going to the amp? I just left that one unplugged since I grounded the new amp in the tire well.

 

There were three wire harnesses plugged into the factory amp:

1. Low level in
2. Speaker out
3. Power wires (includes factory sub output)

I only used the first 2 and left the power one hanging (tied off). Should I ground the ground wire from this harness?

 

The ground wire in the power harness should already be connected to ground.

You need to isolate your signal RCAs from the ground.

There may be a wire in the factory input harness that will connect to the radio chassis. This wire can be connected to the shielding of the RCAs to pull the noise back through the radio.

 

Thanks Ed. I'll see what I can find.

Good luck reaching the upper 150's! I can't even imagine that amount of sound. My two 10" P1s are unbelievably loud for me but I guess your not cranking it that high during your daily commute.

 

Thank you,
I tune it low for daily driving but can easily crank it up when I have to.

Good luck getting the noise to go away.

 

Just FYI for those that may have a similar problem. I tried grounding the low level signal shield back to the radio chassis. Turns out the radio chassis is grounded to the car's power ground. (I confirmed continuity to the car chasis.) It made a pretty nasty noise when I grounded to the radio but no harm done. A ground loop isolator helped but didn't solve the problem. I finally ran a new rca cable tapped right at the radio and this seems to have solved the problem. I've yet to run it permanently so I'll need to determine the best route. It's going over the seats for now.