JoeBoost

Finally got around to doing the big 3 upgrade. Getting to the alternator was a bit of a PITA as all the air ducts have to be removed to get any kind of decent access.

There is no way to get 0ga and the factory 4ga through the (+) hall sensor so had to get a bit creative.

I left the factory alt to battery run in place
Ran 0ga on top of that from alt to 3-way distro block mounted on battery box.
Moved the factory run to the distro block
Ran 0ga from distro block, through the hall sensor to battery

Ran 0ga ground from alt mounting bolt to chassis

Ran 0ga ground from battery (-) to body. There is a second hall sensor on the (-) side but I was able to get the 0ga and factory grounds to fit through it. For whatever reason its larger than the (+) sensor.

clpeller

How long did it take you? I have to do this on my '11 5.0 SCrew as well.

JoeBoost

2.5 hours +- of actual install/cable fabrication. Wasn't rushing and stopped for "refreshments" as I went along. Planned it out in my head beforehand.

Stenz

What does the "big 3" accomplish?

JoeBoost

Maximize current flow of the charging system.

clpeller

Awesome! I was expecting it to take a lot longer than that. I've never done this before because I've never really had a stereo that required it. Thankfully I'll have the help of a very experienced person though.

ibd2328

iTrader: (2)

The alt isnt made or intended to charge batteries, its for "maintaining" the charge of the battery its in parallel with. Of course if your battery is within a few tenths of its maximum voltage, the alt will resupply those volts. But in general, a vehicles alt is only for maintaining current. It's not intended to charge anything.

This is why alot of people who have bad batteries or ones going dead, end up replacing an alt, soon there after.

JoeBoost

The alternator serves two primary functions: power the electrical system/accessories and recharge the battery. Calling it "maintaining" is semantics - it is charging system plain and simple which is why an alternator output is in 13-14v range. It needs to exceed the battery potential in order to induce a charging state. So yes, one intent of an alternator is to charge, recharge, maintain (whatever you want to call it) the battery.

When the electrical system demand exceeds output of the alternator the battery is your reserve. Keeping the battery maintained or charged (again semantics) in as quick and efficient manner as possible (less strain on charging system) is one of the reasons people do the big 3 upgrade.

The other reasons are to stabilize voltage (significant drops are bad) and reduce/eliminate dimming lights. By increasing wire gauge of the "big 3" you increase current flow, e.g. reduce resistance in the overall system. Remember that electricity will take the path of least resistance. 0ga wire is typical.

The battery terminals, vehicle chassis, frame, alt (+) and alt ground (engine block) all make up the 12v system. The alternator is considered the "true ground" of a vehicle which is why I prefer to use an alternator mounting bolt for the engine to chassis run. Its not necessary and any point on the block will suffice...Im just a bit ****.

The big 3 are:

1) Battery negative to chassis
2) Alternator to battery positive
3) Chassis to engine

Some do "big 4" and add another ground from chassis to frame.

Hope this helps.

Joe

ibd2328

iTrader: (2)

Not trying to be argumentive, but you are exactly right; It maintains the batteries charge. Most voltage regulators are strictly rated from 14.4 to 15.2V.

I Just teach college physics, I'm not expert in energy transfer.

JoeBoost

No argument and didnt mean it to come off that way Just stating facts and what little I do know about 12v systems. Im just an IT guy....