So the positive battery cable has that break off wire that goes to the slow-blow fuse. That wire from the fuse goes to the alternator??? There was another post from long ago that I found in a search that talked about that wire going bad and maybe being a little small and showing how to upgrade it. I think I posted a link to the starter of this thread on his other thread, but if what I am putting together from that other post and this post. That is the wire that the alternator connects to the positive battery cable. My battery light comes on where there is no charge going to the battery and then a little while later it will go off. This could be the issue for me. I will have to upgrade all four of the wires to be sure. If I am right, we should change it to the big 4 wires.

1. + Battery to Slow-Blow fuse
2. Slow-Blow fuse to Alt.
3. - Battery to chassis
4. Engine to chassis

Thanks for the insight.

siris

 

If you dont mind me asking, with what parts did you rebuild the alt?

 

I dont have a clue, the guy who rebilt it said he found toyota parts to beef it up.

 

A few notes:
1) You shouldn't parallel fuses/fusable links of X amps. Current travels through both paths and assuming you just added another fuse of X amps, the net result is putting 40 amp fuse in a 20 amp circuit. It'll take twice as many amps to trip that fuse and that can be a bad thing... I'm not saying that you should NOT put a fuse/fuse link - I'm saying if you're using both circuits, you should divide the fusable link by 2 and use 2 of them in parallel.

I always upgrade my electrical system on early toyotas. The factory wiring gauge is simply too weak for 15-25 year old vehicles. I use 4ga wiring to the starter and to both ground points. I see no reason to use better wire than 4ga for our electrical systems.

If you've got a big alternator, replacing that wire should be manditory.. On 1st gen pickups, I've seen the stock alternator wire get old, start to heat up, and generally go bad on that weak-ass 40A alternator. If the wiring is in good shape (it tends to go bad at either end) and you've got a stock alternator, I wouldn't mess with it...

Just my .01.

 

I went with 1/0 everywhere since I compete and every 0.1dB counts, and well, big wire is cool as hell too!

 

Clarification please: Tad bit old I realize, however if I was going to be doing the 'Big 4' as it were, assuming I run:

1. + Battery to Fusible link (?)
2. Fusible link to Alt (4 gauge)
3. - Battery to chassis (4 gauge)
4. Engine to chassis (4 gauge)

Anyone know what size fusible link I should replace the stock one with? The stock seems to be an 8 gauge fusible link if I had to guess.

 

What you might consider instead of a fuseable link is getting one of those big fuses they sell for high end stereo amp wiring (like say 100 amps). I've got one for my main power wire going into the cab that I found at Ultimate Electronics.
It's on the big red cable here right off the battery:

 

I would always carry a spare, or leave the OEM wiring intact as well....

 

Yeah good point.

 

So is it even worth it then to upgrade the fusable link between the battery and the stock fuse box? Am I correct in assuming this would make for better current flow between my optima and the fuse box and alternator and optima?

 

I intend on leaving the factory wiring intact, but adding a 2 or 4 gage battery-alternator with an in line 100 or 125amp fuse

and then run various grounds from various locations, battery to chassis, intake manifold-chassis, block-chassis.

 

IIRC I kept the factory fuseable link in place, I don't think the fuseable link section is long enough to have any measurable voltage drop.

 

The only reason I was going to do this upgrade was I had my OEM alternator rewound to 100amps... and for winching I was going to put a hand throttle in.. well the hand throttle nor big 3 got done, but I will probally beef up the grounds on my 07. The Tow Package has a 130 amp alt, so the wiring shoud be good... but in order to use a chassis ground I want to beef the grounds up...

Back on topic.. I was going to leave the OEM wiring 100% intact and just put a seperate wire from the alt in to the battery, this way I dont have to remove stuff, and if either fuse were to go (doubtful), i had a backup. This would also allow me to run the second wire to the top post, which is the one Optima wants for a winch, so the power would have been more direct.

 

This thread is very helpful, but being an electrical rookie, I am getting frustrated.


My Runner has a bad ground somewhere and is giving me the ever popular single click. I can get it started with jumper cables acting as a faux ground.

Two questions for all you sparkies out there:
1. Where is the chassis to engine ground?
2. Is the negative terminal cable supposed to run to the passenger side motor mount or the block?

 

I don't know if someone already suggested this, but you might try 1/0 ga welding cable. It's much more flexible, durable and "dense" than battery cable. I used it on an old car that I wired from scratch and it worked great!

 

IIRC on my stock 93 ext-cab 3VZ-E:

1. There was a ground from the middle-top of the fire wall to the intake manifold.

You can see the ground here bolting to the intake just behind the V6 3.0 EFI name plate


2. After reviewing some pics it looks like the passenger side motor mount, but the block would work just as good. The wire is off in this pic though.

 

Yeah I used welding cable a lot, but usually not that big. I think the biggest I used was 2 gauge, usually more like 4.

 

will these upgrades work on my 82 4x4 truck. If not ideas please cause my alternator keeps dieing and comming back on causing my battery to die.

 

They will work on any rig, thou I doubt thats your problem.

 

In desperation I replaced that one wire on my truck with an old piece of 8 gauge power cable and some cheap crimp on ring terminals on a whim to see if it would help and it fixed 99% of all of my electrical issues...

Funny thing is that several years back I had a charging issue and the electric shop I had work on it replaced that wire and soldered all of the connections on the replacement. The only thing they did that I questioned was they used a long piece of fuseable link right off the battery that I always wondered how well it would transfer current.

Now that I know that was most of the problem it's time to save up and get larger gauge cable to redo that and the rest of the '3' and add fuses.