"The Big Three" Electrical Upgrade

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How did you fix this? did you cut it down until there wasn't anymore corrosion? Did you have to add any length back to it?


Has anyone made a new fuse box for the main positive ( + ) terminal where the alternator wire goes into? I'm looking at some BlueSea products that might work but I'm not sure where to put it or if the original wires will bend or reach somewhere new.
Sorry, somehow I missed this. I pulled the corroded grounds and replaced them with fresh lengths of 2/0 wire. It’s easy, just make sure your wire cuts are clean and you use a decent crimper.
 
FYI team,

I made some specifics measurements for the Small Battery Fuse box to Alternator, the cable length on my 2000 LC. The cable length is ~88 inches give or take 2-3 inches I would say that's around 7ft 4in

So I count 6 Wire upgrades you can do on the 100 Series LC/LX which are given below -

Power Cables Upgrade (wires coming from Battery (+) Positive terminal) -

  1. - 88inches - Battery (3 fuse box) to Alternator cable length = 88in or 7ft 4in.
  2. - ?? Length - Battery to Starter (But I have not see people change this one b/c of how hard is it to access the starter)

Grounding Cables Upgrade (wires that are either grounded to Vehicle ground points or Battery (-) Negative terminal)

  1. - 9-12' - Battery Negative to Fender right next to the battery - The short wire. is around 9-12' inches in length.
  2. - 26' - Engine hook (next to the oli cap) to chassis ground (in front of the fuel filter)
  3. - 30' - Engine block (Rear engine hook) to back Firewall - This one is slightly different on 98-2003(2004?) where this ground to the engine is not on the rear hook. 2005-2006 the ground is on the Rear hook. However you can just move all years to the rear engine hook. So the ground wire will run from back firewall to rear engine hook
  4. - ?? length - Engine block to battery Negative terminal - Some also run this cable which is connect via the thick cable wiring coming to the battery (-)
 
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My Update. I was able to update my Grounding cables to 1/0 cables. Here are some pictures.

I am also selling these 1/0 cables at the small business front Link here ---> Big 3 Grounding Cable Upgrade here

Fender to Engine hook Mount Ground Wire Shown Below (Engine facing forward) with Plastic Motor Bracket Removed.
Fender to Engine GW_LI with Text.jpg



Fender to Engine hook Mount Ground Wire Shown Below (Facing the Engine) with Plastic Motor Bracket Removed.
Firewall to Engine GW-2 Inked.jpg



Engine to Firewall Ground Wire shown below. Firewall ground wire close to the heater "T's" - Plastic Engine Cover Removed.
Firewall to Engine GW Inked.jpg



Battery Negative (-) to Fender Ground Wire shown below - With mounting points shown in Red
Battery to Fender GW.jpg
 
Thinking of making my own cables, it looks like all of the body mounts grounds are 5/16" lug diamter . Can anyone out there confirm?

Scratch that , just measured m6 bolts so 1/4" eyelets needed.
 
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Thinking of making my own cables, it looks like all of the body mounts grounds are 5/16" lug diamter . Can anyone out there confirm?

Scratch that , just measured m6 bolts so 1/4" eyelets needed.
Yes most grounds are m6 1/4 eyelets.
 
My Update. I was able to update my Grounding cables to 1/0 cables. Here are some pictures.

I am also selling these 1/0 cables at the small business front Link here ---> Big 3 Grounding Cable Upgrade here

Fender to Engine hook Mount Ground Wire Shown Below (Engine facing forward) with Plastic Motor Bracket Removed.
Fender to Engine GW_LI with Text.jpg



Fender to Engine hook Mount Ground Wire Shown Below (Facing the Engine) with Plastic Motor Bracket Removed.
Firewall to Engine GW-2 Inked.jpg



Engine to Firewall Ground Wire shown below. Firewall ground wire close to the heater "T's" - Plastic Engine Cover Removed.
Firewall to Engine GW Inked.jpg



Battery Negative (-) to Fender Ground Wire shown below - With mounting points shown in Red
Battery to Fender GW.jpg
Thank you for posting this. It’s excellent. What about a cable from positive terminal of the battery to the alternator? Is that something you’ve considered and do you think there’s any way to get to the connection on the back of the alternator without removing it?
 
Thank you for posting this. It’s excellent. What about a cable from positive terminal of the battery to the alternator? Is that something you’ve considered and do you think there’s any way to get to the connection on the back of the alternator without removing it?
I just last night, reach down from above, to tighten the nut securing the wire to alternator. It's an easy reach.
I see in post #25, accessing through the fender well. In that post a replacement alternator wire is installed. Using aftermarket wire lug, without pins.

The wires lug has pins (locking blades), that secure it from moving once on the alternator. These these pins, keep wire lug from moving. Any replacement wire lug, should have the pins. Without the pins (locking blades), wire vibration, could loosen the nut. Which could result in sparkes. Certainly result in a short.

In this case last night, battery light was going on and off periodically. But only reported during turns, acceleration, stops & bumps in the road. Alternator was just replaced days earlier, with Toyota remain. Assumption was either loose battery clamp and loose wire on alternator. What we found, was signs of high heat on alternator wire at alternator lug. Which melted the plastic wire cover (found lying below on rack). Also sign of melted plastic on the alternators' wire keep, for wires lug pins and on wire sheathing/heat shrink of alternator wire. The wire lug was moving, not being firmly secured. The movement, must have been causing sparks. I attempted to tight the nut securing the alternator wires. It turned way to easy, an the stud just snapped off. We don't know, if a defective alternator with bad connection/stud or its nut was not properly torque during install. But we're sure, it was shorting/sparking created excessive heat. This can be a fire starter! It must be why Toyota uses a pinnable wire lug and a cap over wire.


Image_2024-05-11 19_24_02_298.JPG
 
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Thank you for posting this. It’s excellent. What about a cable from positive terminal of the battery to the alternator? Is that something you’ve considered and do you think there’s any way to get to the connection on the back of the alternator without removing it?

@Les Summer... I was able to get the alternator to positive battery cable installed as well. Here is the link to the big 4 cable kit.

Also you will obviously have to remove the skid plate to get to the Alternator B+ terminal. But replacing that terminal you do not have to take the alternator out. Its somewhat of a PITA but it is certainly possible to get it done with some arm twisting.

1715523884106.png


1715523910357.png
 
I just last night, reach down from above, to tighten the nut securing the wire to alternator. It's an easy reach.
I see in post #25, accessing through the fender well. In that post a replacement alternator wire is installed. Using aftermarket wire lug, without pins.

The wires lug has pins (locking blades), that secure it from moving once on the alternator. These these pins, keep wire lug from moving. Any replacement wire lug, should have the pins. Without the pins (locking blades), wire vibration, could loosen the nut. Which could result in sparkes. Certainly result in a short.

In this case last night, battery light was going on and off periodically. But only reported during turns, acceleration, stops & bumps in the road. Alternator was just replaced days earlier, with Toyota remain. Assumption was either loose battery clamp and loose wire on alternator. What we found, was signs of high heat on alternator wire at alternator lug. Which melted the plastic wire cover (found lying below on rack). Also sign of melted plastic on the alternators' wire keep, for wires lug pins and on wire sheathing/heat shrink of alternator wire. The wire lug was moving, not being firmly secured. The movement, must have been causing sparks. I attempted to tight the nut securing the alternator wires. It turned way to easy, an the stud just snapped off. We don't know, if a defective alternator with bad connection/stud or its nut was not properly torque during install. But we're sure, it was shorting/sparking created excessive heat. This can be a fire starter! It must be why Toyota uses a pinnable wire lug and a cap over wire.


View attachment 3629991

Good to know @2001LC why the alternator plug used the locking blade terminal post. When replacing with a bigger alternator cable that locking blade terminal does not fit the other terminal lugs. So most people just bent the blades straight to fit that terminal.

Knowing what happened to your problem above. I would think that a Nylock nut would work in that instance as well. If you dont have that which is the case with me. Having to tighten the bolt from time to time would work as well.. I think depending on how much off roading is done.. recheck that nut every year or so.
 
Good to know @2001LC why the alternator plug used the locking blade terminal post. When replacing with a bigger alternator cable that locking blade terminal does not fit the other terminal lugs. So most people just bent the blades straight to fit that terminal.

Knowing what happened to your problem above. I would think that a Nylock nut would work in that instance as well. If you dont have that which is the case with me. Having to tighten the bolt from time to time would work as well.. I think depending on how much off roading is done.. recheck that nut every year or so.
Nylock nut would work okay, as would retorquing. Both ot would be best, too periodically check the nut.

But neither is as good as the way Toyota designed. A one and done locking system, with support bracket for wires.
 
We'll be pulling that alternator this morning. Perhaps we'll get a better idea of why it shorted and stud failed. The owner who also is the installed of the alternator. Is and electrical engine, we'll be working together today.
 
@2001LC @BnvS
It's funny how I even came about this thread, so I'll share. So I live in the city, and if you leave a vehicle unattended long enough in the parking lot, mice will get in and chew your harness. They get a thrill off of chewing wires with current running thru them. Ask me how I know. Anyway, I learned that Grandpa's peppermint scented mouse packs drive them nuts, because they can't stand the smell with their highly sensitive noses. So I had one of these zip tied to my AC lines up by the battery, and so I change them out with new packs every few months. It's crazy because I accidentally knicked one of my AC lines about 6 months ago, almost severing it, when I was cutting off one of those stupid zip ties to replace the mouse pack. So the other day I was replacing the mouse pack in the same spot, and forgot scissors existed again, and so I was going at the zip tie with my knife, slipped, and knicked my ground cable going from battery to fender, and actually cut a few of the conductors. I was boiling pisssed at myself. I was looking to maybe solder the wire, and in the process ended up finding this thread on a google search. Now here I am looking at doing an upgrade.

I assume there is an advantage to doing just the big 3 upgrade without doing the alternator to battery connection, so I'm going for it.

After reading here I'm given second thoughts on doing the cable from alternator to positive terminal, and maybe it'd be better for me to not disturb it. I'm on a bad luck streak right now. I can do my timing belt and water pump, but I'm too clumsy to cut off a zip tie.
 
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I just last night, reach down from above, to tighten the nut securing the wire to alternator. It's an easy reach.
I have little t rex arms, but ill see if I can reach even if I don't do the wire upgrade from alternator to battery..
 
We'll be pulling that alternator this morning. Perhaps we'll get a better idea of why it shorted and stud failed. The owner who also is the installed of the alternator. Is and electrical engine, we'll be working together today.
Pulled alternator and best guess:.

Alternator Wire Nut, not torque to 7ft-lbf and wire housing hanger bracket not secured to alternator. Resulting in, alternator wire harness & lug movement. Loos wire resulting in very high resistance (heat) and sparks, melted plastic and change hardness of nuts metal studs.
 

BTW Great work, That last cable you did was way longer than necessary... you need that ground to go from the Engine to the Firewall. All I did was to run it to the closest engine bolt as shown below. Does the same thing..and is a shorter wire run instead of running it around/over the engine. But great work non the less.

1732709951604.png
 
I'm working on installing the kit from @BnvS on my 2007 LC. I have the composite intake manifold so I cannot attach the ground to it. The provided firewall to engine ground is too short to reach anything... unless I'm missing something obvious. From what I can see the factory ground comes from the firewall, to a connector and then disappears into the corrugated loom. I presume it is the same ground that comes out of the loom on the passenger side and attaches to the hook.
IMG_7558.jpeg

IMG_7560.jpeg

IMG_7561.jpeg

IMG_7562.jpeg

The only way to reach this hook is to increase the length of the cable. I tested with the provided alternator cable to get an idea of layout and length.
IMG_7563.jpeg

IMG_7564.jpeg


If anyone has alternative suggestions I'm all ears.
 
I'm working on installing the kit from @BnvS on my 2007 LC. I have the composite intake manifold so I cannot attach the ground to it. The provided firewall to engine ground is too short to reach anything... unless I'm missing something obvious. From what I can see the factory ground comes from the firewall, to a connector and then disappears into the corrugated loom. I presume it is the same ground that comes out of the loom on the passenger side and attaches to the hook.
View attachment 3865475
View attachment 3865476
View attachment 3865477
View attachment 3865478
The only way to reach this hook is to increase the length of the cable. I tested with the provided alternator cable to get an idea of layout and length.
View attachment 3865480
View attachment 3865481

If anyone has alternative suggestions I'm all ears.
I'd suggest attaching the new cable to the location I marked in red = you can either "double-up" for the ground or remove the "thin" OE...but attach the new cable at the same locations. (there's a bolt at each end)

IMG_7558.jpeg
 
I'd suggest attaching the new cable to the location I marked in red = you can either "double-up" for the ground or remove the "thin" OE...but attach the new cable at the same locations. (there's a bolt at each end)

View attachment 3865717

So attach the big ground wire to that tiny thing? What would be the point of that? Why would I even bother upgrading it at all?
 

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