Main body earth (Negative) link location

[CBR Jeff]

Help needed.

I know what it is but for the life of me I cannot remember where it goes.

The main body earth link wire. It’s about 250mm long and a 4mm wire. Can someone let me know where it goes from and too on a standard car please. Almost the last piece of the under bonnet puzzle.

Jeff

[C.A.R.]

Bonnet catch to top of tappet cover.

[CBR Jeff]

Thanks Mr Fowler. I like the new ears!

Jeff

[PB260Z]

[gilltech]

Was this the result of a Nissan service advice note or something? Mine doesn't have one, nor do most of the Zed engine bays I've looked at online.

[PB260Z]

23 hours ago, gilltech said:

Was this the result of a Nissan service advice note or something? Mine doesn't have one, nor do most of the Zed engine bays I've looked at online.

Hi

Not sure, but it was the location on the original motor in my '77 Bus.

There are certainly tidier places to put it, and I have been tempted to relocate it to somewhere less visible.

Cheers

PB

[CBR Jeff]

23 hours ago, gilltech said:

Was this the result of a Nissan service advice note or something? Mine doesn't have one, nor do most of the Zed engine bays I've looked at online.

They must have it installed some place or the earth circuit would not work. My car had it installed (originally) at the bonnet latch. I worked that much out as it was in the container with the latch but could not remember where the other end went. I have put it back as Mr Nimoy and PB have said and as it was originally and it looks ok.

Jeff

[gilltech]

Mine earths through the thick cables to/from the starter motor and also there's a thinner earth wire connected between the negative battery post and adjacent firewall. Does your car have the latter wire?

[Cozza]

On 4/29/2019 at 10:05 PM, gilltech said:

Mine earths through the thick cables to/from the starter motor and also there's a thinner earth wire connected between the negative battery post and adjacent firewall. Does your car have the latter wire?

This is how my 240z is too.

If the battery negative is connected to the motor only, with no connection to the body, how do the tail lights etc. work? Don't they have an earth return through the body?

The motor is theoretically isolated electrically from the body by the rubber engine and gearbox mounts.

[Riceburner]

6 hours ago, Cozza said:

This is how my 240z is too.

If the battery negative is connected to the motor only, with no connection to the body, how do the tail lights etc. work? Don't they have an earth return through the body?

The motor is theoretically isolated electrically from the body by the rubber engine and gearbox mounts.

Mine is the same as you two as well but I also have a small earth from one of the dizzy retaining bolts across to the coil bracket.

[CBR Jeff]

Thanks boys. The fine earth wire from the negative terminal to the fire wall will be the same wire just a different location. I’m guessing that either the factory changed it over the years or it’s been relocated for good looks. 

Jeff

[KatoKid]

10 hours ago, Cozza said:

This is how my 240z is too.

If the battery negative is connected to the motor only, with no connection to the body, how do the tail lights etc. work? Don't they have an earth return through the body?

The motor is theoretically isolated electrically from the body by the rubber engine and gearbox mounts.

Too true......my dad had a new battery put in his VL Commodore years ago and whoever installed it forgot to refit the smaller body earth wire to the -ve battery terminal. A couple of weeks later my dad calls to say that the auto trans T bar shifter handle is getting really hot......turns out the shifter cable was acting as the body earth back through the engine/trans.

[gilltech]

Quote

Thanks boys. The fine earth wire from the negative terminal to the fire wall will be the same wire just a different location. I’m guessing that either the factory changed it over the years or it’s been relocated for good looks. 

The fine earth wire on mine is not a separate wire as such but rather is permanently attached with the main negative cable to the battery terminal. If your main negative cable has been replaced with an aftermarket cable then that will be why you have the separate wire. There is a threaded bolt hole in the firewall just above the battery where the factory fine earth wire is intended to be attached.

[Cozza]

That’s it Katokid. After rebuilding my first mini I didn’t put in the earth strap and the outer choke cable melted on first start up as it was acting as the earth.

mine too Gilltech, i can’t take a pic of mine at the moment but it sounds just the same as yours. 

Edited May 3, 2019 by Cozza