Alternator Fuse and Fuse Box-Battery Wire Replacement/Upgrade

traced all my wires and they are buried inside that harness. know where everything goes now I think. I am trying to reduce wiring with this mod, so instead of adding I'm replacing. I am picking up an "engine battery wire harness no. 2" tomorrow. My plan is to carefully take it apart then upgrade the powers and grounds and reuse the plugs and connectors it comes with. I worried about getting it done in one afternoon, so got another harness instead. That way I'm not in a rush and have the original if I screw something up. I can post pics when I do if anyone is interested. Appreciate all the replys so far. Loving tacomaworld.

 

I actually traded that truck in shortly after this happened for an 18 and never really figured out why it happened. The only electrical modification that the truck had was a brake controller plugged into the factory harness spot. I was pumping gas when it happened. Went to start the truck and everything was just dead. The only thing I can think of is I think when I went to start the truck the gas pump was still attached to the truck which I never do - don't remember why I did that time. Maybe it created some kind static or something though? Really have no idea.

 

Big thanks to @Chuy

Took a dry run today before I replace all my wires for the big 3/4. I would not of been able to get to that final bolt without this thread. Now I know I can do it.

 

success. thanks again OP and those who answered my questions.

 

Does anyone knows where can i find the 140 Amp Fuse, or whats the part number?

 

OEM -

$20 90982-08286 Fusible Link

90982-08286. The Bussman FLB-140 may fit but I don't that anyone has confirmed that.

 

Thank you so much for detailing how to get that 140 amp sob outta there
Without your write up I’d have been out there with a chisel and an oscillating tool lol

 

You're Freaking a Life Saver TY!!

 

For those looking to do big 3 with high output alternator, you will run a heavy gauge cable (1/0) from alternator to fuse to battery. You will also leave your stock wire going to fuse box. It is recommended to upgrade this wire too but 2 or 4 gauge will work. It is also very important to run the same size cable (1/0) from alternator mounting bolt (preferably on block side where it straddles the block mount) to battery negative to complete the ground circuit. Yes the alt is grounded to block and block to battery but this is critical to do.

Lastly, upgrade your starter cable and battery to block ground with same size (1/0) cable as this is all one circuit.

 

This may be a silly question, but if you upgrade the wire and want a higher amp fuse can you bypass the PDC/fuse box?

IMG 4, bottom left corner, where does that wire normally go
, or what is the purpose of that terminal?

Does that go to the alternator or is it a ground terminal?

I did the upgrade but want to install a 250a ALT

 

@fishizzo That terminal in img4 is also in top right of the next image. I am pretty sure the cable from the alternator goes there. As part of my 200-amp alternator and dual battery install, I rewired that alt to fuse box wire. I changed that wire to 1/0 and rerouted the wire to a block terminal (similar to Fastronix 406-251). From the block terminal, I ran a wire to the fuse panel, and then a 2 gauge to my 2nd battery, and added an inline 200 amp fuse.

Leaving the 2nd battery out of the picture, you can run a 2 gauge wire from the block terminal to the car battery and add an inline fuse. With the 250 amp alt, You need to upgrade the alt wire. Otherwise you will overheat the alt when it nears its max output as it tries to push power through oem wiring designed for oem alt output.

 

It seems like most "Big 3 upgrades" bypass that 140 amp fuse. They run a cable directly from the battery (+) to the (+) lug on the alternator itself. Since there is no 250 amp fuse that I can find for the DC Power Inc 270 amp alternator it seems adding a thick bypass makes the most sense; especially since all other individual electrical parts in the Taco are fused. The Alt fuse seems like a redundant failure point for those of us that need more energy to run the rest of our thirsty electrical parts. If you know I am wrong, please offer an explanation for it.

 

It’s the only fuse for the fuse box itself so it’s not redundant at all. Similar to the fuse or breaker for an auxiliary fuse panel or the main panel breakers on your house as opposed to the individual circuit fuses or breakers. Get away without it? Not going to publish a recommendation online for that.
Btw, op does a fused jumper wire so it’s all still protected. Basically the 140A fuse protects the panel and the fuse on the jumper protects the jumper.

 

They don't bypass it, they ignore it. It is irresponsible, imo, if an upgrade kit’s instructions doesn't mention to add a fuse to any new alt to battery connection. Any positive wire connecting to the battery needs to be fused in the event of a short. Even the wire to the starter is indirectly fused via the starter’s solenoid.

Here is a vendor that does mention it.
https://www.kicker.com/app/misc/support/tech/tech_papers/docs/TheBig3Upgrade.pdf

 

The Big 3 kit from DC Power Inc has a 250 amp inline fuse. I spoke to a DC Power Inc representative on the phone. He says you add the upgrade cable to the existing cables; just put one more on the studs and crank down the nuts.

 

140a “fuse” blew. Replaced it.

whoever designed this hands on sight.

I hope there is an upgrade out there for this garbage.

I like how it’s not water-sealed to begin with. And that it’s 100 times worse of a design than “unreliable brands”

 

That seems wrong. Each cable should be individually fused or replaced with a single, thicker one. It may seem okay since the cable capacities add up but they still aren’t a single cable and shouldn’t be treated as one.