DIY - Big 3 Grounding Kit

[Hard_oNe]

DO-IT-YOURSELF Big 3 Grounding Kit.

I'm a do-it-yourselfer type of shade-tree mechanic. Saving money helps me buy more mods. So are others members like SVOSHOP and DVelasco68, this post I give credit to them. My purpose is to share with others like us the information needed to build your own Big 3 Grounding Kit.

PARTS LIST #1 (Hard_oNE):
100-196 4 AWG Black High Current Power Cable.. 8'..... $1.75/per foot
095-656 Gold Ring 4 AWG 5/16" 2 Pair .. 4ea... $4.24/ea
263-631 StreetWires BAGMT GM Truck Adapter .. 1ea... $7.89/ea
080-720 NTE Heat Shrink 2:1 Black Assorted Size .. 1ea... $3.76/ea
Total: $42.61 + shipping

PARTS LIST #2 (DVelasco68)
Part Number In Stock Description ....................................Qty Price Ext. Price
100-194 Yes 4 AWG Red High Current Power Cable 1 ft ... 2 $1.75 $3.50
100-196 Yes 4 AWG Black High Current Power Cable 1 ft.. 4 $1.75 $7.00
360-622 Yes 6-1/2" Wire & Cable Cutter .......................... 1 $5.95 $5.95
095-656 Yes Gold Ring 4 AWG 5/16" 2 Pair ....................... 2 $4.24 $8.48
263-631 Yes StreetWires BAGMT GM Truck Adapter .......... 2 $7.89 $15.78
080-720 Yes NTE Heat Shrink 2:1 Black Assorted Size ...... 1 $3.76 $3.76
UPS Ground $9.22
Total: $53.69

http://www.partsexpress.com


Here is SVOSHOP original post with pictures. I had fun to do it myself with limited tools. I hope you'll find the information informative and helpful. A added advice for those of you with wet weather or rust prone location, apply 3M™ Scotchkote™ Electrical Coating. It will help seal the ends and protect it against moisture, corrosion and other contaminants.

Stay safe and have fun.

SVOSHOP Complete post with Pictures:

Originally Posted by SVOSHOP

Per the request of members on here. I managed to take a few pictures today. I am not saying to do this to your Blazer, but it sure worked wonders on mine.

I started with buying different battery bolts. The 8mm that screws into your battery can be changed out with a type of extender. It screws your main power wire into the battery, and then gives room for you to add on a wire, secured with a nut. You need to start with a set of those.

With the battery disconnected, I found the power wire on the back of the alternator. I bought another power wire ( around 12 inch, 4 Gauge ) and ran it along with the factory power wire. I connected that second power wire directly to the positive post on the battery.


Power Wire on Alternator


Other end of wire, connected to battery


I then took my second cable. ( Another one about 12 inch and 4 Gauge ) Black this time, and ran it from the ground marking on the alternator bracket, directly to the negative battery post. I use the same bolt to hold my catch can in place.

Alternator bracket, note it says GRND on the casting


Run directly to the negative post


The third and final wire, I used another 4 gauge and it is about 20 inches long. The parts store only had red for this size. However, it will be used as a ground.

I did some research and found the ground on the front passenger side head was common for a missfire on other GM vehicles. Ours were excluded, but I thought it would be a good place to run a secondary ground. I removed the factory ground, cleaned it up, and reinstalled it along with my new secondary ground.

Front passenger side head


I ran it over to the passenger side fender, buy the coolant bottle.


And that was it. Reconnect the battery and be amazed That you no longer have a missfire at idle.

I personally ran wire loom and kept everything clean looking. You do not have too, but I seems to dress it up.

The money shot.


Good luck.

Mike

[Warwagon]

The misfire at idle does NOT completely go away with a big 3 grounding kit. Stop claiming it does!

Notice how the 2 OEM black battery wires run through the sensor in front of the battery? The new ground from the battery to alternator bracket should also run through this. The above pictured routing from the negative battery post bypasses this current sensor. (Others have successfully routed this extra ground wire through the sensor.) Pic from:
http://ss-shootout.com/powerman.html


Edit:
After measuring the voltages with the engine running there is a 0.5v measurement between the engine and frame. This is enough to justify doing a kit like this.

[jetttstream]

My GM battery terminals are available separately and are a LOT cheaper than 15 bucks!

Great post/summary nonetheless!

-Mike

[Kenny_Cox]

Thanks for posting that up, I was going to attempt to find where they grounded to the block and you just made it THAT much easier

[DVelasco68]

$15 is for two of them....

and it's DVelasco68 not: PARTS LIST #2 (DVelasco58)

Originally Posted by jetttstream

My GM battery terminals are available separately and are a LOT cheaper than 15 bucks!

Great post/summary nonetheless!

-Mike

[SRL]

Or you could just go to your local car audio shop and pick them up for a few bucks... We sold them for like $4-5 at Best Buy. We also had a smaller thing of 4 Gauge power wire for a pretty reasonable price too. All Rockford Fosgate stuff (their newer power wires are very very nice and very flexible, almost as good as the old Purple Lightning Audio stuff)

[Hard_oNe]

Originally Posted by DVelasco68

$15 is for two of them....

and it's DVelasco68 not: PARTS LIST #2 (DVelasco58)

My apology for misspelling your name. I corrected it.

[DVelasco68]

No offense taken, I was just making one correction (figured I'd make the 2nd one)...

2 for 1 sale....

Originally Posted by Hard_oNe

My apology for misspelling your name. I corrected it.

[VettePwr]

Originally Posted by Warwagon

The misfire at idle does NOT completely go away with a big 3 grounding kit. Stop claiming it does!

Notice how the 2 OEM black battery wires run through the sensor in front of the battery? The new ground from the battery to alternator bracket should also run through this. The above pictured routing from the negative battery post bypasses this current sensor. (Others have successfully routed this extra ground wire through the sensor.) Pic from:
http://ss-shootout.com/powerman.html

can you please explain why it needs to also run in that sensor. ty

[Warwagon]

Originally Posted by VettePwr

can you please explain why it needs to also run in that sensor. ty

This system uses current going in and out of the battery to choose between charging and fuel economy mode - several other modes exist. Fuel economy mode drops the alternator voltage and allows the battery to discharge some. Old systems used a fixed voltage that always charged the battery. This constant charging voltage is not true on this new system.

Bypassing the current sensor with another heavy ground wire can mess up the current reading by 50% or so. (Parallel circuits resistance/current rule.) For example lets say you are using 6 amps from the battery in fuel economy mode but the sensor is only seeing 3 amps because the other 3 amps are going through the 'bypass' wire. 3 Amps is the cut off discharge rate for staying in the fuel economy mode. 6 amps should kick the alternator voltage back up and stop battery discharge. However because of the wire that bypasses the sensor the system only see 3 amps and will let the battery drain regardless of voltage.

Same can be said for charging the battery.

So you want this wire to go through the sensor so your system can make proper decisions off of complete data. The system's effectiveness under any conditions is up for debate.

Edit:
As grounding kits are the hot topic I posted up GM thinking on how the current sensor is supposed to work. It is a complicated mess. Doc here: http://www.tbssowners.com/forums/showthread.php?t=27319

[VettePwr]

ty for explaining that to me. i just finished running that ground and i was able to slide it easly through the sensor. You just have to move the wires so they dont overlay each other which makes more room to get the wire in there.

[Karch]

Originally Posted by VettePwr

ty for explaining that to me. i just finished running that ground and i was able to slide it easly through the sensor. You just have to move the wires so they dont overlay each other which makes more room to get the wire in there.

Did you buy Alvin's kit? If so, how was the ground cable long enough to run through there?

Thanks.

[VettePwr]

i made my own.

[JAY4SPEED]

Nice write up fellas!

Look at Joshua kickin' the knowledge! And he's 100 accurate as usual

[ogwap]

It seems to me you would be double counting that charge (block to fender wire) if you add it to the sensor. The circuit (- battery post to frame) is already being counted in the existing factory wiring so anything you add to the frame ground (such as audio amps, etc) will also be metered by the sensor.


edit: misread something
Added battery to frame grounds such as the - battery terminal to the alt bracket should be added to the sensor.

[redlead3]

so do all the "3" need to run through that sensor?

[Warwagon]

Only the wires connected to the neg bat post need to run through the sensor. Usually only 1 wire.

[TBSSinhawaii]

Very interesting. You wanna give me a hand at this Hard?

[timg]

Originally Posted by Karch

Did you buy Alvin's kit? If so, how was the ground cable long enough to run through there?

Thanks.

I bought Alvin's kit. The ground is not long enough to run through the sensor. I haven't seen any bad effects yet, but I have only driven a few miles since installing it. I'll post more results later.

Tim

[Islandman]

I want to try this mod but I'm concerned about the new lead from battery (+) to the alt. The factory wiring includes a fusable link. If crunched the wrong way, this cable will burn.

Will protecting this lead defeat the purpose?

BTW: I miss the days when the fuse box was under the dash. The accessory wiring runs were much shorter with less resistance for the size/lenght used. Common location on most vehicles these days is under the hood with nice long 16-18 gage wiring runs. With the current they pull, no wonder our windows are so slow. I bet a 6-8 gage power lead to a window motor would speed things up.

Just a thought.