I say Remove the entire Grounding system, and see if the noise is there without it. Then re-install it.

 

This may be a long shot too....
Disconnect the positive lead going to the amp at the battery terminal and see if the noise goes away.

Dmitry

 

Remove the kit immediately – it doesn’t sound like you know what you are doing. I don’t want you to hurt yourself OR your Z.

 

Someone change his name too...

 

I believe he had his friend make an SN for him, which caused confusion the first place months ago.

Anyhow, I wonder if anything is getting in the way with the connections. The only spark (surprise) I got was when the wire to negative terminal slipped from me and touched the positive terminal a few times before I managed to catch it. Fireworks display anyone? Yes... I got a lil nervous there.

 

Hi
first thing is that if you put all the ground wires in correctly, then there should not be any issue. You might have accidentally bent something when you were installing, so this whatever-it-is might be causing something to hit a fender or the firewall when you are running. I would look at the throttle cable routing.
The biggest concern is the low voltage on the voltmeter. This would suggest a fault in the alternator (it is an internal excited single wire type)- check the wiring around the power plug, and listen in that area. and sniff too. You should read 13-14 volts at idle. If you are reading 12V, you might have a problem in the wiring of the stereo head- maybe the power line is touching something? intermittently??? Although, IF your system is properly fused, the fuse should blow (unless somebody put a really heavy duty fuse in the line). Check the power feeds to the power amp- there may be a loose connection there.
Good luck.

Had another thought- when the power cables were installed for the amp- were they protected or put into a grommet when they were fed through the firewall>??? This could lead to a shorting situation, but I would not think it would be regular in beat.

By the way- the extra ground wires look cool, but really do not do anything (see some of the other non-inflammatory responses to your question) for the engine or ground (I posted about this a long time ago). My measured ground resistance is on the order of a few milliohms, which will not be altered by some extra grounding wires. Although the service mechanic will not thank you when you need major engine work....
GOOD LUCK!!!!

 

1) Do the above. If the problem doesn't go away, the car needs to go to Nissan!

2) Make a new screenname. It's causing you way too much work man.