Hi there, just a quick question really

Can you use the negative terminal on the battery to ground things when wiring?

Or is this bad practice?

Should you never ground to the battery and always ground to the chassis?

Cheers

you can...but in practice most people run an earth to a sturdy looking bolt or screw on the bodywork

do people do this for any particular reason? or just the fact that it was probably the easiest thing to do at the time

Easiest really, they all go to batt anyway :s

Surely you get to a point where the earth strap from body to batt would need uprating for the extra earths on the car?

Saying that, shouldn't be any current tbh as components use it all eh

Harris is on to something there as you can over ground the chassis, causing some nasty electrical faults.

http://www.innovatemotorsports.com/resourc...l-grounding.php

an tbh the stock earth is a bit pathetic, so its always worth adding one or two extra from the battery.

On the MK2, the earth clamp is a cheap pressed steel item which connects only to the inner wing. But on 6n/2 they're a cast fitting and have two ground points (first to the body, then on to the gearbox).

So to help with earthing mine after starter issues, i found the thickest of two i had (one a 1.4 CL 6n and one from a 6n2 GTi with air con) and fitted that instead - with the cast clamp to the battery, the intermediate link to the inner wing, then it goes on to bolt to the cylinder head. And all perfectly spaced.

It's not often you can pull a part from one VW and have it fit great as a two-minute straight-fit upgrade to a completely different model, VW often seem to work hard to engineer stuff so that it's not easily interchangable, but this is a nice exception (At least with the 16v head anyway, dunno if it'll reach an 8v head quite so well).

Yeah I was considering earthing mine up.

Bit off the point, but mikey, do you know if a 6n live cable (one to starter, then alternator) would fit on a mk2/3 and reach to the batt? starter and alt in the same place but dunno about length to batt?

Battery terminal clamps are designed to be corrosion resistant, this is the main reason why it is generally recommended to earth your components away from the actual battery terminal.

The battery negative lead has to carry all of the starter current, the starter drawing more current than any other item. Once the engine is running, there is no way that you could overload this lead, other than by a dead short!!

Back in the 'olden days', cars had Negative earth, but in the 1950s, it was decided to move to Positive earth to avoid corrosion problems at the battery terminal, this worked well, except for the fact that all of the bulb holders, and more importantly, the car body itself started corroding, so someone had the great idea to go back to 'plan A'

Regards.

Nick, i also use a 6n2 GTi positive lead (as with a 6n2 GTi starter motor and 6n2 GTi alternator). It's almost the same length, just a touch longer, and the cast terminal fitting has four bonafide anchorage terminals on it for auxillary wiring.

Safe

Here you can just make out the negative lead pretty much all the way along. I've ran it in front of the battery and out the panel, but alternatively it could run straight out along under the wing join and across that way.

I used the 6n2 starter/live lead on my mk3 aswell

Been reading more into earthing and its apparently more important with things that go to the ecu temp sensors ect to earth them at individual points on the block in order to avoid any unwanted noise signals.

So i'm just gonna earth the block to the chasis twice then earth the ecu ground cables to seperate locations on the engine.

I was just thinking because I'm running the 6n 1.6 starter and the mk3 wires look pieces of shit haha

You'll need to upgrade, it's the only thing that solved my problems with a very slow starter. I tried different starters and 440a battery, all that is a thing of the past now since beefing up the wiring.

Yeah, I mean the AEE always cranked into life easily on the mk4 but that had a bigger batt! I have a 520CCA for the mk3 to go in, only 53aH though.

Will defo be using the mk4 cables then! Although I think I lost the earth one haha.

How come you didn't connect the ground to the batt?

wow ignore the above bit, couldnt see on my phone lol!

threw my 6n ground cable away dammit!

No reason why you shouldn't ground straight to the battery in my experience. Most of my engine bay components ground to the chassis leg now, but I have used the battery neg as a ground before and no problems.

On the latter note, tri-rated 25mm square cable will also do for the starter/alt cables if you can't get your hands on the original VW straps/harnesses.

What kinda weird arse top mount caps are they mikey?

What kinda weird arse top mount caps are they mikey?

They're off a Punto bladeback. They're excellent, still no movement even with shot top mounts, and the thick rubber underside dampening rings keeps the top mounts quiet even if you're on a cobbled street.. Plus they can take up bare angle gap, ideal for those of us running extra castor.

The plastic-trimmed deep cups that were standard on the Polo are absolute crap because they have no margin whatsoever.

What kinda weird arse top mount caps are they mikey?

They're off a Punto bladeback. They're excellent, still no movement even with shot top mounts, and the thick rubber underside dampening rings keeps the top mounts quiet even if you're on a cobbled street.. Plus they can take up bare angle gap, ideal for those of us running extra castor.

The plastic-trimmed deep cups that were standard on the Polo are absolute crap because they have no margin whatsoever.

Ahh i see, you and your custom mods

I forget half the shit i've done, the gearshift gatier is from a Perouda Nippa or something equally random, horn i'm thinking a 306, the bonnet strut there is a Saxo item.. Even the battery is taller than a Polo one - thinkit's for a Toyota Aygo 1.5D.

I really should write it all down before i go completely senile.

love it man, good variety haha