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Discussion Starter #1
I want to replace the battery earth lead and install a quick release connector. Can I use two separate leads instead of the Alfa one which connects to the body and then gearbox?

If so any ideas of the length required?
 

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I want to replace the battery earth lead and install a quick release connector. Can I use two separate leads instead of the Alfa one which connects to the body and then gearbox?

If so any ideas of the length required?
Yes you could do. You could buy a couple of metres on a roll, cut it to length and crimp on your own ends. Its all readily available on ebay.

I use the original Alfa one which for the 156 GTA (except selespeeds) is 60663787, approx £60+VAT.

Late model GTs have quick releases on the negative cable, the part number for these is 50504458 and they are less than £40+VAT. I don't know for sure they fit but they should do, battery is in the same place, chassis is in the same place, gearbox is in the same place and of the same type...

I've changed quite a few earths now, they are starting to become problematic.
 

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I've changed quite a few earths now, they are starting to become problematic.
Any particular symptoms or just the usual low voltage histrionics?
 

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Discussion Starter #4
Mine hasn't shown up any faults, but there is much corrosion on the lead where it connects to the chassis hence wanting to change it.
 

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Discussion Starter #5
GTA lead £66:96

GT lead £40:14

Both + VAT. Considering the GT one has a QR fitting work that out! Me thinks a metre of cable and a few connectors is calling!
 

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Any particular symptoms or just the usual low voltage histrionics?
Just the usual stuff really, same problems as what bad batteries cause. So cranking is usually a giveaway that there is either a battery or earth problem.
 

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Hi Toxic,
It’s a while ago, but what did you end up doing on this? Any links to what you bought? I stripped my battery tray out yesterday to paint it up and wanted to have the earth strap off, but 12mm wanted to round the nut off, 11mm wouldn’t fit and no imperials would fit. It looks easier to get to from the underside anyway. It’s something I’d like to replace, but if you found a solution that cost a lot less than £40, do tell.

Also, are there any more major earth points worth cleaning up? I have a feeling i did 2 on my 159.
 

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I would also appreciate any information about the required length since I already have the components and I could prepare the lead in advance :)
 

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Discussion Starter #9
The original cable was a one piece from the battery to the chassis and then to the gearbox. I replaced this with two 500mm lengths of 35mm2 tri-rated flexible cable with lugs (8mm mounting holes). I also bought a Quick release terminal, this required removing one of the lugs.

https://www.ebay.co.uk/itm/35mm-Earth-Strap-Cable-for-Battery-Motor-Boat-Car-Various-Lengths-/162039466494?var=461007907183

https://www.countybattery.co.uk/terminals-clamps/fuller-quick-release-terminal-negative-70mm-118mm-1000-amp/
 
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Thanks Toxic,
I had a very brief glance at the chassis bonding point, but just thought it was a cable tidy, hence why I was asking if there are any other earth points worth looking at. Now with the battery, tray and air box back in and after reading yours and Pud’s posts properly, I can clearly see a big chassis bonding point?, could’ve easily had that off and cleaned it up earlier today.

Thanks for the links, I’ll give them a go at that price. Cheapest I could see the QR GT cable was in Italy and it’s over £25 postage!

When you cut the lug off, did you feel like cable clamped up okay with just the screws or did you solder it too?
 

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I want to replace the battery earth lead and install a quick release connector. Can I use two separate leads instead of the Alfa one which connects to the body and then gearbox?

If so any ideas of the length required?
I would not do it. You risk creating an "Earth loop" and potentially risking electrolytic action.There could be other issues, vis a vis any loop acting like an aerial picking up noise and getting into sensitive devices - engine management - radio - etc. In fact you could produce a multitude of unintended loops. Alfa did not do it that way by chance.:rambo:
 

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I would not do it. You risk creating an "Earth loop" and potentially risking electrolytic action.There could be other issues, vis a vis any loop acting like an aerial picking up noise and getting into sensitive devices - engine management - radio - etc. In fact you could produce a multitude of unintended loops. Alfa did not do it that way by chance.:rambo:
I’m a long way off knowing much about electronics/electrics, so apologies if this sounds as thick as pig crap. I wasn’t thinking about modifying the lead, just looking for a similar much cheaper alternative. I took the airbox and battery tray back out this morning, Xmas boredom��. Cleaned the chassis earth up and measured the lead to see if it’s the same as the 156 lead. I wonder if the earth cable, battery to gearbox, is one piece and the chassis clamp is just crimped on about 35cms from the battery. It doesn’t seem like there are two cables within the sheathing. So if 2 new cables are used, one from battery to chassis and then one from the same chassis clamp to the gearbox, how would that be different to the original?
 

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I’m a long way off knowing much about electronics/electrics, so apologies if this sounds as thick as pig crap. I wasn’t thinking about modifying the lead, just looking for a similar much cheaper alternative. I took the airbox and battery tray back out this morning, Xmas boredom?. Cleaned the chassis earth up and measured the lead to see if it’s the same as the 156 lead. I wonder if the earth cable, battery to gearbox, is one piece and the chassis clamp is just crimped on about 35cms from the battery. It doesn’t seem like there are two cables within the sheathing. So if 2 new cables are used, one from battery to chassis and then on same same chassis clamp, one the gearbox, how would that be different to the original?
If you are saying, one earth lead going from the battery to the chassis, terminated with a lug to a bolt/nut and then a second lead fixed to the same chassis nut/bolt and on to the gear box, that's fine. Just make sure the two lugs on the chassis bolt/nut are nice a clean - use some electro-grease and connect the two faces of the lugs together with no washer in between - direct lug to lug contact. In effect this is just one cable, picking up the chassis on route to the gear box. Or the other way round picking up the gear box on the way to the chassis. That might be the better way as there is some suggestion it is block earthing problems which are causing coil packs to burn out.
 

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Discussion Starter #15
If you are saying, one earth lead going from the battery to the chassis, terminated with a lug to a bolt/nut and then a second lead fixed to the same chassis nut/bolt and on to the gear box, that's fine. Just make sure the two lugs on the chassis bolt/nut are nice a clean - use some electro-grease and connect the two faces of the lugs together with no washer in between - direct lug to lug contact. In effect this is just one cable, picking up the chassis on route to the gear box. Or the other way round picking up the gear box on the way to the chassis. That might be the better way as there is some suggestion it is block earthing problems which are causing coil packs to burn out.
That's exactly what I did, keeping the original routing just using two cables rather than the original single cable.
 

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Discussion Starter #16
Thanks Toxic,
I had a very brief glance at the chassis bonding point, but just thought it was a cable tidy, hence why I was asking if there are any other earth points worth looking at. Now with the battery, tray and air box back in and after reading yours and Pud’s posts properly, I can clearly see a big chassis bonding point?, could’ve easily had that off and cleaned it up earlier today.

When you cut the lug off, did you feel like cable clamped up okay with just the screws or did you solder it too?
It was securely clamped without being soldered.
 

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All good then, cheers Chaps. Next question, cable temperature rating, a lot of the cable is rated up to 70*C, is that enough for inside the engine bay? It’s not like it’s in contact with the engine or any pipe work.
 

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All good then, cheers Chaps. Next question, cable temperature rating, a lot of the cable is rated up to 70*C, is that enough for inside the engine bay? It’s not like it’s in contact with the engine or any pipe work.
It's the insulation rating, not the cable. Insulation is rated up to X degrees working temp. Other than starting, there is no heavy current in the cable - continuous current - and the cable is multi stranded, which has better current handling capacity and needless to say gets less hot than a single conductor or one with fewer strands. So the "internally generated heat will not exceed 70 degrees under normal conditions.

Crimping and soldering the lug will increase the low impedance area and make better lug to cable contact - improving current handling capacity and reducing the potential for electrolysis and volts drop. But providing the cable is properly crimped with the correct crimp tool for the lug/cable, it will be fine. Not as good, but fine!

But if you are going to solder, it's a big lug and a big cable. So you need a very hot source to "Flow" the solder quickly - and proper flux. If the solder does not flow properly it might just as well not be there as there won't be proper physical and electrical bonding, and can result in electrolytic action, degrading the quality of the termination. And it needs to flow quickly to avoid the risk of degrading/melting the insulation of the cable.

Hobson's choice! If you think you are good enough and have all the right tools, crimp and solder - fine. If not, stick with proper crimping - pressure of some crimp tools/lugs/cables, particularly if they are heavy, can be tons per square inch in industrial applications. None the less, in this instance, pressure on the tool needs to be very high.
 

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If you are saying, one earth lead going from the battery to the chassis, terminated with a lug to a bolt/nut and then a second lead fixed to the same chassis nut/bolt and on to the gear box, that's fine. Just make sure the two lugs on the chassis bolt/nut are nice a clean - use some electro-grease and connect the two faces of the lugs together with no washer in between - direct lug to lug contact. In effect this is just one cable, picking up the chassis on route to the gear box. Or the other way round picking up the gear box on the way to the chassis. That might be the better way as there is some suggestion it is block earthing problems which are causing coil packs to burn out.
Can't go searching for coil pack burn out thread, so thought I would just attach it to this one about earth wiring.

It is not something I considered but as I was researching "Manifold Catalytic Converters", this little snippet popped up out of the text. May be un - related, but the source seams to be quite authoritative.

"Any condition that causes abnormally high levels of unburned hydrocarbons—raw or partially burnt fuel—to reach the converter will tend to significantly elevate its temperature, bringing the risk of a meltdown of the substrate and resultant catalytic deactivation and severe exhaust restriction. Usually the upstream components of the exhaust system (manifold/header assembly and associated clamps susceptible to rust/corrosion and/or fatigue e.g. the exhaust manifold splintering after repeated heat cycling), ignition system e.g. ((((((coil packs)))))) and/or primary ignition components (e.g. distributor cap, wires, ignition coil and spark plugs) and/or damaged fuel system components (fuel injectors, fuel pressure regulator, and associated sensors) - since 2006 ethanol has been used frequently with fuel blends where fuel system components which are not ethanol compatible can damage a catalytic converter - this also includes using a thicker oil viscosity not recommended by the manufacturer (especially with ZDDP content - this includes "high mileage" blends regardless if its conventional or synthetic oil), oil and/or coolant leaks (e.g. blown head gasket inclusive of engine overheating). Vehicles equipped with OBD-II diagnostic systems are designed to alert the driver to a misfire condition by means of illuminating the "check engine" light on the dashboard, or flashing it if the current misfire conditions are severe enough to potentially damage the catalytic converter"
 
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