Big Three upgrade Question

[bubbatrucklover]

Sorry Kris I'm not trying to make the question hard to understand. I guess I think people can read minds.

In the big three up grades I see,people LEAVE the stock wire and distribution block and ADD the extra wire and in line fuse. In my case I REPLACED the distribution block and wire with ought gauge and fuse and 4 gauge ground but, DIDN'T add a second wire and fuse.

Is the reason people leave the factory wire and block is because they are trying to help a factory alternator keep up with the load where as with me having a high out put alt and ought gauge there is no real reason to add the 2nd wire and fuse but, add a second battery and isolator when the time comes?

 

[M.Cueva]

Sorry Kris I'm not trying to make the question hard to understand. I guess I think people can read minds.

In the big three up grades I see,people LEAVE the stock wire and distribution block and ADD the extra wire and in line fuse. In my case I REPLACED the distribution block and wire with ought gauge and fuse and 4 gauge ground but, DIDN'T add a second wire and fuse.

Is the reason people leave the factory wire and block is because they are trying to help a factory alternator keep up with the load where as with me having a high out put alt and ought gauge there is no real reason to add the 2nd wire and fuse but, add a second battery and isolator when the time comes?

Yes. many people leave the factory wires and blocks in place to leave the factory charging system intact (and all the little connections that go with it). The Big Three is designed to allow more current to pass directly to the battery and provide a better ground for high current loads. On newer trucks, the factory ground wire has a sensor on it that helps tell the computer when to turn on/off the alternator (GM Variable Charging).

The factory wire may or may not handle your upgraded alternator's output (depending on age/condition) and the added stress of any other power demands. Remember the basic principal: try to force too much water through a garden hose and it will burst. Same goes for the wiring, try to put too much and your wiring will heat up and fail.

As for the second battery, if you plan on running just one alternator on both batteries, the upgraded wiring allows you to get the most power to each with no issue.

I had the same thoughts as yours so I went with the biggest wire that I could find. Hope his helps answer your question.


attached are a couple of shots of the factory wire vs the upgraded one.

 

[Z71 Kris]

Sorry Kris I'm not trying to make the question hard to understand. I guess I think people can read minds.

In the big three up grades I see,people LEAVE the stock wire and distribution block and ADD the extra wire and in line fuse. In my case I REPLACED the distribution block and wire with ought gauge and fuse and 4 gauge ground but, DIDN'T add a second wire and fuse.

Is the reason people leave the factory wire and block is because they are trying to help a factory alternator keep up with the load where as with me having a high out put alt and ought gauge there is no real reason to add the 2nd wire and fuse but, add a second battery and isolator when the time comes?

Yes. many people leave the factory wires and blocks in place to leave the factory charging system intact (and all the little connections that go with it). The Big Three is designed to allow more current to pass directly to the battery and provide a better ground for high current loads. On newer trucks, the factory ground wire has a sensor on it that helps tell the computer when to turn on/off the alternator (GM Variable Charging).

The factory wire may or may not handle your upgraded alternator's output (depending on age/condition) and the added stress of any other power demands. Remember the basic principal: try to force too much water through a garden hose and it will burst. Same goes for the wiring, try to put too much and your wiring will heat up and fail.

As for the second battery, if you plan on running just one alternator on both batteries, the upgraded wiring allows you to get the most power to each with no issue.

I had the same thoughts as yours so I went with the biggest wire that I could find. Hope his helps answer your question.


attached are a couple of shots of the factory wire vs the upgraded one.

yeah what he said...and no worries about it...

 

[bubbatrucklover]

Yes. many people leave the factory wires and blocks in place to leave the factory charging system intact (and all the little connections that go with it). The Big Three is designed to allow more current to pass directly to the battery and provide a better ground for high current loads. On newer trucks, the factory ground wire has a sensor on it that helps tell the computer when to turn on/off the alternator (GM Variable Charging).

The factory wire may or may not handle your upgraded alternator's output (depending on age/condition) and the added stress of any other power demands. Remember the basic principal: try to force too much water through a garden hose and it will burst. Same goes for the wiring, try to put too much and your wiring will heat up and fail.

As for the second battery, if you plan on running just one alternator on both batteries, the upgraded wiring allows you to get the most power to each with no issue.

I had the same thoughts as yours so I went with the biggest wire that I could find. Hope his helps answer your question.


attached are a couple of shots of the factory wire vs the upgraded one.

yeah what he said...and no worries about it...

Thanks Mike and Kris. The highlighted pretty much answers my question.
I wasn't really grasping why anyone would keep the factory wiring in the mix.

What's funny is I've been doing "the big three" to every vehicle I've ever owned. Just didn't realize that's what it's called.

 

[bubbatrucklover]

Oh and Mike, I like the page you have in your link with the mods and work you've done on your Silvy.

 

[M.Cueva]

Oh and Mike, I like the page you have in your link with the mods and work you've done on your Silvy.

no problem, though I have not had a chance to update that site with all the changes, updates for several years now...oh well....time is my biggest commodity and I never have enough.