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Discussion Starter #1
When you work on Land Rovers that were "fixed" be shops and POs, you often see bad wiring choices that go well beyond crimp connectors, wire nuts, suitcase connectors, and so on,
While these are poor choices the worse is 2 wires twisted together and insulated with a few wraps of electrical tape.

Here are a few pictures of what I think is the worst possible wiring choice you can make: the connection directly to the battery ground.
Not only do they get into the way, but they can cause a fire.
When wires are connected directly to the battery ground and run separately to electrical devices, if the main ground connection is lost, then when the starter is engaged, it will attempt to draw the entire 100+ amps of voltage through the small ground wire(s) that immediately catch fire.
I already removed the 3 wires, but you can see where the ring terminals were connected to the ground terminal.
I'll ground them to the body with a star washer and screw.
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Discussion Starter #2
While I am at it, will move the wires that were connected directly to the (+) terminal to the starter lug so they don't get in the way when the battery terminal is disconnected.
If you keep crushing the ring terminal when it is tightened and twisting it when moving the main cable, eventually the thin ring terminal will distort and break off.
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IMG_20201015_150745112 (1).jpg .
 

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Or use military style positive terminals where the clamp bolt is separate from where the wire connections are made.
 

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There's nothing wrong with properly-done crimped connections. Done correctly with proper tooling and technique they'll form a gas-tight connection that's more reliable than a soldered connection. Plenty of things have flown in space with pressure (e.g., crimped) connections.

But to your main point, there should rarely be any need to directly connect to the battery terminals, and should be done with great care. On a high-capacity AGM battery those terminals can deliver 2000+ amps into a dead short. Think carefully about failure points and what type of currents will flow when bad things happen.
 

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Discussion Starter #5
Depends on the crimp connector.
Most crimp connectors are aluminum, not tin plated copper.
The aluminum crimps oxidize and has metal reaction with the copper wire and creates resistance.
Over time the resistance can build to a point where the voltage drops or is all but completely blocked.
The other reason to avoid crimp connectors is they can vibrate loose.
Most owners couldn't perform a robust crimp if they had to.
 

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Depends on the crimp connector.
Most crimp connectors are aluminum, not tin plated copper.
The aluminum crimps oxidize and has metal reaction with the copper wire and creates resistance.
Over time the resistance can build to a point where the voltage drops or is all but completely blocked.
The other reason to avoid crimp connectors is they can vibrate loose.
Most owners couldn't perform a robust crimp if they had to.
I have a really good crimping tool but only use crimp connectors when intended to be temporary or on something inconsequential. I have seen all the issues Robert mentions.

I really like the butt type solder connectors you use a heat gun to melt the solder. I wish I could find them in ring and blade connectors.
 

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I've installed a few Sniper EFI systems and the manuals specifically tell you to connect to the battery terminal (both + /-). Wonder why they would do that.
 

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I'm always shocked when I see wires twisted together without any solder and just wrapped with tape. I noticed on the Td5 and Puma trucks the negative lead from the battery connects to both the chassis and the t-case or gearbox which is a nice safety measure. There isn't a spot there on the chassis to connect it to on mine so I made a short 1/0 cable to connect the Puma negative to one of the gearbox mounting bolts.
 

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The vast majority of crimp connectors I've seen have been tin-plated copper. Done with proper tooling and technique, they form a gas-tight cold weld connection. And they're more resistant to vibration since the individual strands stay separated and the wire remains flexible, as opposed to when they are fused into a solid strand with solder.

The vast majority of connectors in factory harnesses are crimped on.

 

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I try never to butt join wires or tap into existing wires unless absolutely necessary. I was always crimped connectors and used shrink tubing with adhesive in vehicle wiring and rarely ever solder anything. I was taught that solder connections were brittle and should be used in fine electronics that are free from vibration while pressure connections if done properly can join on a molecular level.
 

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Depends on the crimp connector.
Most crimp connectors are aluminum, not tin plated copper.
The aluminum crimps oxidize and has metal reaction with the copper wire and creates resistance.
Over time the resistance can build to a point where the voltage drops or is all but completely blocked.
The other reason to avoid crimp connectors is they can vibrate loose.
Most owners couldn't perform a robust crimp if they had to.
I've done a lot of electrical work on my boat (less on the rover) - and the ABYC standards require crimping as solder-only connections are prone to damage from vibration. I've never heard of a good crimp being vulnerable to vibration. I use Ancor heat-shrink connectors that are pure (tinned) copper, and with their special crimping tool it makes it a breeze to do perfect crimps every time.
 
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