Big 3 Upgrade help

[thomaspuzio]

I want to help my electrical out after installing an aftermarket head unit and sub with sub amp.

Has anyone performed the "big 3 upgrade" on the engine wiring?

1. Alternator to positive battery
2. Battery Negative to chassis ground
3. Engine block to chassis ground

I see 1 and 2 easily, but i'm unsure where the engine block to chassis ground wire is located. I think there is a fairly thin wire performing this function which is visible from the passenger side of the engine bay, towards the firewall. However, the wire I saw which is bolted to the engine block, goes into a large group of wires and disappears somewhere behind the engine.

If I attempt to do this upgrade, where should I attempt to do the 3rd wire ground? Also are there any warnings you may have?

 

[07V8]

I want to help my electrical out after installing an aftermarket head unit and sub with sub amp.

Has anyone performed the "big 3 upgrade" on the engine wiring?

1. Alternator to positive battery
2. Battery Negative to chassis ground
3. Engine block to chassis ground

I see 1 and 2 easily, but i'm unsure where the engine block to chassis ground wire is located. I think there is a fairly thin wire performing this function which is visible from the passenger side of the engine bay, towards the firewall. However, the wire I saw which is bolted to the engine block, goes into a large group of wires and disappears somewhere behind the engine.

If I attempt to do this upgrade, where should I attempt to do the 3rd wire ground? Also are there any warnings you may have?

Unless you’re pushing a ton of power, it’s not needed. I’m at over 3000W RMS with zero indication of the wiring being a weak point. It’s been installed for 10 years and 185k miles for reference.

 

[TowMeOut]

Somebody will probably correct me but I think in our factory configuration our ground splits just past the battery post connection and goes to the fender (chassis ground) and down to the engine block. I've never traced it out but I know the ground cable splits so that's where I assumed it goes.

I was kicking this around after adding the fridge and winch. So far both seem to be quite happy with the existing wiring. I'm sure there are some gains to be had from adding bigger cable and better quality (mil-spec) clamps but for me they don't seem to justify the expense.

I'm looking at adding a 2nd battery either under the hood (regular flooded) or possibly in my storage system next to the fridge (AGM). If I go under the hood I'll be adding quite a bit of extra cable and will probably be forced to upgrade several items at that time.

Good luck and let us know how it works out....pics please!!

 

[riceandpho]

I want to help my electrical out after installing an aftermarket head unit and sub with sub amp.

Has anyone performed the "big 3 upgrade" on the engine wiring?

1. Alternator to positive battery
2. Battery Negative to chassis ground
3. Engine block to chassis ground

I see 1 and 2 easily, but i'm unsure where the engine block to chassis ground wire is located. I think there is a fairly thin wire performing this function which is visible from the passenger side of the engine bay, towards the firewall. However, the wire I saw which is bolted to the engine block, goes into a large group of wires and disappears somewhere behind the engine.

If I attempt to do this upgrade, where should I attempt to do the 3rd wire ground? Also are there any warnings you may have?

depending on the engine you have, on the 4.0 at the front of the engine, behind the bracket under the intake is a good place to ground back to battery, when i change out my alternator, i use the bolt at the alternator instead.

 

[thomaspuzio]

my main concern is slightly low charging volts from my alternator.

I replaced my battery (Optima Redtop type 35) after three years because it was low (12.06v), but still under warranty and Pep Boys said they'd put in a new one free (vs recharging it). My alternator, with no load was 14.05v, and with load it was 13.92v. I'm thinking that a combination of shorter trips, reduced truck usage, and a larger draw from my radio has created a perfect storm of diminishing returns on recharging my battery. To the point that after awhile the battery will dip into the area of causing damage, and always be in a perpetual state of not fully charged.

So my thinking was, if I upgrade my big three, I could increase the current heading to my battery from the alternator and therefore recharge my battery more efficiently.

As for engine to chassis, I'm wondering if I can just add a new one wherever i see it'll fit.

Thoughts?

 

[thomaspuzio]

depending on the engine you have, on the 4.0 at the front of the engine, behind the bracket under the intake is a good place to ground back to battery, when i change out my alternator, i use the bolt at the alternator instead.

This is the Limited with 4.0 v6

So are you saying the engine block gets a ground wire to the negative terminal on the battery? I thought it gets a ground wire to the chassis (at least that's what all the "big three upgrade" articles I've read state).

https://jlaudio.zendesk.com/hc/en-us/articles/204374080-The-Big-3-Wiring-Upgrade

 

[ZiaMan]

If you are concerned about that - you should look at a bigger alternator or a battery maintainer like the Optimate6

 

[Drunner97]

I want to help my electrical out after installing an aftermarket head unit and sub with sub amp.

Has anyone performed the "big 3 upgrade" on the engine wiring?

1. Alternator to positive battery
2. Battery Negative to chassis ground
3. Engine block to chassis ground

I see 1 and 2 easily, but i'm unsure where the engine block to chassis ground wire is located. I think there is a fairly thin wire performing this function which is visible from the passenger side of the engine bay, towards the firewall. However, the wire I saw which is bolted to the engine block, goes into a large group of wires and disappears somewhere behind the engine.

If I attempt to do this upgrade, where should I attempt to do the 3rd wire ground? Also are there any warnings you may have?

I ran the engine ground from the bolt on the alternator to the negative on the battery. I can take a pic tomorrow when I get home when it's lighter if you want.

 

[RAD4Runner]

Checking, cleaning and tightening your connections are better than any upgrade.
However, if you insist on up-sizing wires...

...So are you saying the engine block gets a ground wire to the negative terminal on the battery?

Correct, grounds are best connected directly to battery negative; body (inner fender) directly to battery negative, engine block, directly to battery negative.
I do not think there is a chassis ground. Chassis is the frame on which the body mounts. It would not hurt, though.

 

[riceandpho]

This is the Limited with 4.0 v6

So are you saying the engine block gets a ground wire to the negative terminal on the battery? I thought it gets a ground wire to the chassis (at least that's what all the "big three upgrade" articles I've read state).

https://jlaudio.zendesk.com/hc/en-us/articles/204374080-The-Big-3-Wiring-Upgrade

itll work, block to battery, battery to fender and also battery positive to alternator. you can also add another ground from block to fender by the dipstick.
here some pics , not too clear i think.

 

[thomaspuzio]

did you replace the factory cables or just add to them?

those pictures look like all new wires everywhere from the battery, but what I've read and seen on youtube everyone just adds to what's already there with an additional wire.

What's the "right" way?

also, where does the battery negative to engine block cable attach exactly (at the engine block)? I can't seem to find where that wire goes.

 

[Drunner97]

did you replace the factory cables or just add to them?

those pictures look like all new wires everywhere from the battery, but what I've read and seen on youtube everyone just adds to what's already there with an additional wire.

What's the "right" way?

also, where does the battery negative to engine block cable attach exactly (at the engine block)? I can't seem to find where that wire goes.

I ran as additional wire. You can go either way, but the proper way would likely be to replace/upgrade existing. I've been running bypassed with dual batteries and a 240a alt for almost 2 years now, no issues other than my battery light flashes at me when I red line it getting on the freeway. I just try not to red line it. heh.

 

[riceandpho]

did you replace the factory cables or just add to them?

those pictures look like all new wires everywhere from the battery, but what I've read and seen on youtube everyone just adds to what's already there with an additional wire.

What's the "right" way?

also, where does the battery negative to engine block cable attach exactly (at the engine block)? I can't seem to find where that wire goes.

i just run it along with the stock cables.

 

[thomaspuzio]

I feel like perhaps I should consider replacing my battery terminals
Mine look pretty weathered. Also they don't really touch the posts but at two points because of how they are designed (like two rings not a solid sleeve)

 

[thomaspuzio]

I ended up completing this task by adding three lengths of 0 guage wire. I did NOT remove any factory wires.

1. First wire I attached to the positive terminal of the alternator and the positive terminal of the battery
2. Second wire I attached to the negative terminal of the battery and the body panel ground. I decided that because I purchased a custom length cable, and that 0 Gauge just doesn't bend, I would mount it under the stock negative ground point. I made sure to clean off the paint first.
3. Third wire I attacked to a bolt on the passenger side of the engine. It looks like a bolt that's helping hold the engine together and nothing else was on it. I cleaned off the aluminum before attaching the cable. The other side I grounded to the passenger side body ground. Just about where the horn is, there's a factory ground wire. I again cleaned off the paint and attached it there.

Afterwards, I noticed a slight increase in voltage from my battery when idle, as well as a quicker recharge than I had before.

The sound system seems to have perked up a tad bit as well. My bass (which is running off it's own amp) is most noticeably louder. I'm thinking the added grounding helped complete the loop or something. Or perhaps removing and reattaching the power wire to the battery (which I had to do to add my new alternator power wire) simply made a better contact this time.

 

[riceandpho]

it sounds louder maybe since you have stabilized the voltage. usual voltage gain is at 13.8 I think on stock alternator. can dip to low 13.3 or 13.4 at idle.

 

[RAD4Runner]

Nice.
Anything we do to minimize voltage drops to components/systems is good. However...

...
1. First wire I attached to the positive terminal of the alternator and the positive terminal of the battery....

Did you verify that this^^^ did not bypass your fusible links / fuse network designed to protect stock wiring? This you can find out by examining the schematic closely.