Earth Points

[ali2992]

Is there a benefit for having multiple earth points? I have 2 for front/dash loom and 2 for rear loom, and I'm wondering if I need an extra one at the front as there's headlights still to be connected yet. Or am I ok using the existing earth connections?

[sj-bradley]

You would ideally use one earth point to prevent earth loops, but on cars it's not so essential as the car is a pretty good EM shield and conductor at the same time.

 

It's just convenient to run one wire to a light and use the car as the earth return instead of two wires. So, choose whatever is easiest.

 

Simon

Edited February 22, 2015 by Simon B

[ali2992]

Thanks, that makes sense, wasn't sure if I was missing some complex issue regarding large circuits or something!

[speedtripledan]

Just make sure your battery to chassis earth is a good one and you will be fine, just use the most convenient points for circuit earths.

[snowy2]

Earth wires should be up to handling the current of the consumers to be earthed......a skinny 1A wire for your rear lights is going to fail sooner rather than later.....

[fry61]

Would doubt there is a 1amp wire for car electrics --- think 10amp lowest = 120watts nominal load.

[sj-bradley]

Some of the more modern cars will have thinner wires specifically for sensors etc like the crank, camshaft ant temperature senders which do not need heavy duty wires.

 

So, you will find that size wire in cars now, just not for anything heavy duty like lights.

 

Simon.

[MarkBzero]

If I remember correctly you need a separate earth point for the fuel level sender, part of IVA not that mine was checked.

[fry61]

Think that should be " A separate earth wire for the tank " ensures the tank remains earthed even if fuel sender (& its earth) is removed;; will prevent a static charge build-up which could be discharged between tank & earthed chassis.

[FERRINO]

I don't trust chassis earths (especially when it's a flat crimp onto a round tube as on the 2B). Whenever I've had electrical probs on a tin top it's always-always been traced down to a corroded or just generally rubbish chassis earth.

 

So with that in mind (and the fact we use them at work on the panel wiring), I'm using one of these at front of the car and one at the back. All the individual earths will be terminated on these and then a proper connection taken back with wire directly to the battery. The chassis will be still be earthed of course with a proper connection back to the battery - but I won't be relying on the chassis connections for lighting and sensitive ECU earths.

 

Cheers

Tony

 

http://www.ebay.co.uk/itm/Neutral-Earth-Bar-JEW103A-100amp-Brass-Bar-/181666937270?#ht_300wt_1043

[ali2992]

Think that should be " A separate earth wire for the tank " ensures the tank remains earthed even if fuel sender (& its earth) is removed;; will prevent a static charge build-up which could be discharged between tank & earthed chassis.

 

ahh, that's an important point as I was about to use the same earth connection as the sender

[blue]

I also run all my earths into batches eg front of car say lights and indicators to one point then use a stainless set screw and nut with a cable large enough to handle the power back straight to the battery.

 

[fry61]

Being a mains sparkie ( retired ) I used several " Tenby Earth Clips " for a good solid connection to the round s/steel tubes; several earth conductors could be terminated in the large screw clamp.

 

And, being "old school" all joints were soldered or at least the strands of the wires were soldered before clamping.

 

Goole shows pictures of the clamps

Edited February 23, 2015 by florin metal works

[MarkBzero]

That's correct;

"All metal fuel tanks must have an earth path to prevent the build up of static electricity. (this may be a separate bonding or the mounting arrangement where it does not isolate the tank)"

[Ben Donlevy]

I have a z cars Hayabusa, Mini Sprint with a GRP Body, Its not Charging I have a Earth to the Chassis, Do I need to Earth the Engine too , Car Does Start