stand alone voltage control and big 3 upgrade?

**Pikey** · 02-01-2013, 12:54 PM

I have a 2005 yukon xl and am looking at doing a big 3 upgrade. My question is, there is a box on the negative battery cable of my truck. if I do the big 3, do I need to run the grounds thru this device? I think it is for the Stand alone Voltage Control, that is designed to adjust alternator output as needed and keep the battery charged at 80%. Will running the grounds away from this effect my truck's charging system?

**Jamm3r** · 02-01-2013, 03:15 PM

A photo might help. Usually there's a red plastic plastic splice box in the positive cable where the cables for the alternator, starter, and battery come together.

**Pikey** · 02-01-2013, 11:54 PM

Originally Posted by Jamm3r

A photo might help. Usually there's a red plastic plastic splice box in the positive cable where the cables for the alternator, starter, and battery come together.

Here it is. On the other side it has GMSAVC written on it along with a part number. From the little research that I have done, it does not look like a good idea to go around it. As you can see there is not much room in the clamp for another wire. Maybe I will just clean the grounds for the battery. Then, install new grounds for the engine to frame and cab to frame. I just noticed in the pic how you can see the salt from the roads creeping from the wheel wells. Looks like it will be time for another engine detail soon!

Click image for larger version.

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**Pikey** · 02-05-2013, 01:25 PM

anyone have any ideas?

**Conlan Rose** · 02-05-2013, 01:44 PM

@SurrealOne might know, his truck is just a year older than yours and he did a major electrical upgrade.

**Pikey** · 02-05-2013, 01:52 PM

The 2004 trucks that I looked at did not have it. Maybe his did. Guess we will find out

**SurrealOne** · 02-05-2013, 11:56 PM

No box on my negative connection -- just the standard red plastic box on the positive connection.

**Toymyster** · 02-06-2013, 04:19 PM

That box does not connect to ground. It is only clamped to the ground cable. GM calls that box the Generator Battery Control Module. From what I gathered, it acts as a voltage regulator. If you are just looking for a ground, anywhere on your engine or chassis will do.

**Enkeiavalanche** · 02-06-2013, 04:38 PM

What are you doing that you need the Big 3?

**Pikey** · 02-06-2013, 08:54 PM

Originally Posted by Toymyster

That box does not connect to ground. It is only clamped to the ground cable. GM calls that box the Generator Battery Control Module. From what I gathered, it acts as a voltage regulator. If you are just looking for a ground, anywhere on your engine or chassis will do.

I never said that it was connected to ground. My post clearly states that it is clamped around the wire. I am concerned that if I run the big three and basically bypass the module then I am not going to have the correct alternator output.

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Originally Posted by Enkeiavalanche

What are you doing that you need the Big 3?

I want to do it because I have some future mods in mind. I also get some severe dimming of lights when I roll the windows up. The battery and alternator are brand new.