Single main + cable to a Anderson plug

[Clarky]

The grounding side of things is just as important as the power.

Using the body as a ground is fine for anything low current but when you are talking 50+ amps resistance in the body is a factor so run a second cable equal the size of the positive cable. Otherwise you run the risk of intermittent voltage drop and can place stress (and overheat) on the factory grounds.

[Ed..]

Originally Posted by Clarky

The grounding side of things is just as important as the power.

Using the body as a ground is fine for anything low current but when you are talking 50+ amps resistance in the body is a factor so run a second cable equal the size of the positive cable. Otherwise you run the risk of intermittent voltage drop and can place stress (and overheat) on the factory grounds.

That is quite a valid point, and I will be measuring what the resistance is first to see which way I go.

[Kiwi Jeeper]

Originally Posted by Clarky

The grounding side of things is just as important as the power.

Using the body as a ground is fine for anything low current but when you are talking 50+ amps resistance in the body is a factor so run a second cable equal the size of the positive cable. Otherwise you run the risk of intermittent voltage drop and can place stress (and overheat) on the factory grounds.

People sometimes make the same mistake with grounding an electric winch. I always take it back to the battery, even if I have to get new electric cables for the winch.

[Ed..]

Originally Posted by Kiwi Jeeper

People sometimes make the same mistake with grounding an electric winch. I always take it back to the battery, even if I have to get new electric cables for the winch.

Likewise, although with the winches I have installed I have always replaced the supplied cables with much heavier ones, I found that usually the supplied cables are way too small for my liking and on a sustained heavy load of several hundred amps such as on a winch, they will heat up the cable which uses more current drain for no benefit.

[sarg]

It seems most people seem run a separate earth cable but you really do need to consider the distance. If you are doing a long run to the back of the car then the resistance can be quite high. In this case, the car body will offer less resistance. Alternatively you would have to increase the wire gauge to reduce the resistance.

However I wouldn't use the towbar as the earth point because you don't know what the connection to the chassis is like (Loctite on the bolts for example). There will be a chassis earth anchor near the rear. On the latest model there is an anchor behind the rear left hand trim.

The following article explains some of the issues if any is interested.
http://www.w8ji.com/negative_lead_to_battery.htm

[Kiwi Jeeper]

So ground to the chassis/body in the back, but upgrade the battery to chassis/body ground strap might be a better solution for such long run?

[Barboots]

Electrolysis. A friend had ongoing issues with coolant discolouration and corrosion in a Brunswick V8 equipped GQ. After taking numerous unsuccessful steps to combat it, the owner was convinced to run earths to the not-insignificant number of the accessories and added/modified circuits. Fixed it.

In my MY14 I've run two core of 3B&S from the battery, via the sill duct, over the wheelarch into the boot, and out to the towbar. Challenge level 3 out of 10. Just run both.