I had an installer tell me that when doing a bigger install in the z that its a good idea to run larger cable from the neg- on the battery back to a distribution block to use as the main ground for the amps instead of using a chassis ground point. He was saying that the chassis ground method on the z doesnt give a good enough ground and alternator whine and other feedback can be the result. Does this guy know what hes talking about? I thought this would be the best place to resolve this issue. Thanks

 

I dont get these installers half the time they dont know what the hell they're talking about. Basically depending on the size system the z electrical should be upgraded to make it more effiecent. The z comes with 8 awg batt to chassis ground which is very thin.
Search Big 3 which is 3 grounds..1. Neg batt terminal to chassis 2. Pos Batt term to pos alt. term. 3. engine block to chassis.....The idoit installer will say it will add whining but he's wrong. Google big 3 it will give a better explanation. Use 4 awg at a minimum but I would do 0 awg. It will reduce or eliminate dimming all together depending on the rest of your electrical. Please dont pay someone to do this mod it is very easy. goood luck

 

Thanks for the info duro78, definitely plan on upgrading my grounding under the hood. I know what you mean about some installers though, they think they have an electrical engineering degree after working in a future shop install bay for a month as a shop sweep....lol.

 

the negative battery terminal is grounded to the chassis...just like u would ground the amp in the hatch...the LAST thing u want is a long ground...the shorter the better...doru78...your on the right track...big 3 is essential...do a big 3 and a deep cycle battery and your straight...good luck and do yourself a favor and do some research and try it by yourself....youd be surprised what u can do if u try...

 

Does anybody know if the Z uses the same system that other Nissans use where the on-board computer monitors and regulates the voltage by measuring the current through the ground wire?

Let me pop my hood and check.

Nope - unlike the Xterra there is no sensor on the grounding wire - the size of which strikes me as rather small.

 

OP, I would run away from that shop and never have them touch your car!!!

 

Since the Z is a uni-body it is hard to get a good ground and there are plenty of threads about alternator whine here. Running a ground distribution system all the way back from the battery is one way to reduce/avoid the problem. Look at some of the high-end car stereo manufactures trouble-shooting web pages and this is one thing they do recommend for troublesome installations.

 

I couldn't have said it any better myself!!
I got the the big 3 in my Z

One thing i've done is sanding the small area where the ground will be placed. Metal to Metal, not to paint/primer