Upgrading stock alternator to 130/150 amp (2 Viewers)

[TrickyT]

...Since you are looking for making as few wiring changes possible you could maybe consider one other way. Run the new large charging wire through a new fuse to the battery positive and just leave the stock wire on the alternator "B" post. Then unbolt the fusible link in the AM1 box and wrap the battery positive end with tape. This way there is minimum wiring changes and those fuse box circuits would still be fed directly from the alternator through that larger #10 wire...

The downside of this approach is that the 10AWG wire circuit is now protected against shorts by a 150A fuse instead of the "Main 2.0L" fusible link. I've never seen an equivalency table that goes from fusible link cross section area to amperage capacity, so I'm not sure how much of a problem this really is. Normally a 10AWG wire would get fused with a 30A fuse. But the 2.0L fusible link must be of greater capacity than this, since it was designed to handle to the full 80A output of the OEM alternator. Still, if a short occurs you want the 150A fuse to blow and not for the #10 wire to turn red hot and start a fire.

Note that all of the various circuits that the #10 wire feeds have their own fuses, so the only thing that is of concern here is what would happen if the 10AWG white wire shorts to ground because of an accident or because its insulation gets compromised. Perhaps an experiment is in order; connect a 4ft length of 10AWG wire through a 150A fuse to the terminals of a 12v car battery and see what happens. If the fuse blows then I think Bill's suggestion is a viable approach. If the wire turns red hot and the insulation melts then it's not such a good idea. If someone tries this out, please post the results.

 

[Beowulf]

If someone tries this out, please post the results.

With a short video please. Shouldn't take but about 30 to 60 seconds.

-B-

 

[Photoman]

The downside of this approach is that the 10AWG wire circuit is now protected against shorts by a 150A fuse instead of the "Main 2.0L" fusible link. I've never seen an equivalency table that goes from fusible link cross section area to amperage capacity, so I'm not sure how much of a problem this really is. Normally a 10AWG wire would get fused with a 30A fuse. But the 2.0L fusible link must be of greater capacity than this, since it was designed to handle to the full 80A output of the OEM alternator. Still, if a short occurs you want the 150A fuse to blow and not for the #10 wire to turn red hot and start a fire.

Note that all of the various circuits that the #10 wire feeds have their own fuses, so the only thing that is of concern here is what would happen if the 10AWG white wire shorts to ground because of an accident or because its insulation gets compromised. Perhaps an experiment is in order; connect a 4ft length of 10AWG wire through a 150A fuse to the terminals of a 12v car battery and see what happens. If the fuse blows then I think Bill's suggestion is a viable approach. If the wire turns red hot and the insulation melts then it's not such a good idea. If someone tries this out, please post the results.

I’m not sure about that downside. I would ask this question. Does the cruiser run with the battery disconnected? If yes, either the Main 2.0L fusible link or a 150 amp fuse would only protect the small white wire from the battery, not the alternator. In the accident or wire short scenario if the motor was still running it would not matter if either fuse failed as the small white wire would still get output from the alternator. Maybe unregulated.

TrickyT’s point is well taken. Any alterations we make can have consequences. If this is not acceptable, leave it stock. If concerned about TrickT’s point with the above wiring option, fuse the small white wire at the alternator.

Before we pull our hotdogs out for the wire test I need to make a couple corrections.
I said the small white wire was “about” 10 gauge; it’s actually closer to 7 gauge. The 10 gauge wire is 12 inches away from the “B” alternator terminal. Second the fuse link wire measures around 12 gauge not 14 gauge. I measured the copper now instead of “abouting”, first with an American standard wire gauge and then with a micrometer. They still will not be exact but closer to correct.

The diameters of the wires are as follows:
Main charging larger white wire was .160 inches……..~ 6 gauge
Smaller white wire .140 inches……..~7 gauge
Blue fusible link wire .082 inches…….~12 gauge

12 inches from the “B” post on the alternator the .140 inch smaller white wire has 2 wires bugged on. The diameter of each wire is .100 inches…….~10 gauge One of these wires goes to the under hood 15 amp EFI, the other to the headlight relay.
The .140 inch white wire continues through the firewall to the in dash fuse panel. At least 3 other wires are bugged off this to feed circuits in the fuse panel. 10 amp ECU B, 15 amp OBD, 20 amp defog, and 40 amp FL heater. I did not measure these wire sizes nor look where the splices were. To sum up, an ~7 gauge wire runs from the alternator “B” post in to the in dash fuse panel with at least 5 wires bugged off of it some of them ~10 gauge.

Bill

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[TrickyT]

I’m not sure about that downside. I would ask this question. Does the cruiser run with the battery disconnected? If yes, either the Main 2.0L fusible link or a 150 amp fuse would only protect the small white wire from the battery, not the alternator. In the accident or wire short scenario if the motor was still running it would not matter if either fuse failed as the small white wire would still get output from the alternator. Maybe unregulated.

I think it will run with the battery disconnected. But in this scenario it won't stay running long because the wire in question powers the ECU and if it shorts to ground the ECU will go dead and the motor will stop. So the wiring is self-protected in this case.

TrickyT’s point is well taken. Any alterations we make can have consequences. If this is not acceptable, leave it stock. If concerned about TrickyT’s point with the above wiring option, fuse the small white wire at the alternator.

Before we pull our hotdogs out for the wire test I need to make a couple corrections. I said the small white wire was “about” 10 gauge; it’s actually closer to 7 gauge. The 10 gauge wire is 12 inches away from the “B” alternator terminal. Second the fuse link wire measures around 12 gauge not 14 gauge. I measured the copper now instead of “abouting”, first with an American standard wire gauge and then with a micrometer. They still will not be exact but closer to correct.

The diameters of the wires are as follows:
Main charging larger white wire was .160 inches……..~ 6 gauge
Smaller white wire .140 inches……..~7 gauge
Blue fusible link wire .082 inches…….~12 gauge

12 inches from the “B” post on the alternator the .140 inch smaller white wire has 2 wires bugged on. The diameter of each wire is .100 inches…….~10 gauge One of these wires goes to the under hood 15 amp EFI, the other to the headlight relay.
The .140 inch white wire continues through the firewall to the in dash fuse panel. At least 3 other wires are bugged off this to feed circuits in the fuse panel. 10 amp ECU B, 15 amp OBD, 20 amp defog, and 40 amp FL heater. I did not measure these wire sizes nor look where the splices were. To sum up, an ~7 gauge wire runs from the alternator “B” post in to the in dash fuse panel with at least 5 wires bugged off of it some of them ~10 gauge.

~7 gauge should be good for ~89 amps indefinitely according to the chart. And like any copper wire, it will probably handle much more than this for a short period of time. In the short-to-ground scenario it needs to handle a whole lot of current for a short time. Can it handle, for example, the 200% overload of a 150A Megafuse for the 3 1/2 seconds required before the fuse blows? Probably. I certainly feel more confident about it with it being a ~7 gauge wire. In fact so much so that I don't think it's worth doing the experiment I proposed because I'm willing to bet on the fuse blowing.

It's also worth keeping in mind the chances of the failure scenario we are talking about, where the white wire supplying 12v to a bunch of fused circuits shorts to ground somewhere along it's ~6-8ft path between the battery to the two fuse blocks. It certainly could happen, but I've never read a report of it here on Mud and suspect the chances are relatively low. So it's like you said Bill, the alterations we make can have consequences and folks just need to be aware of what they are and assess them from a safety perspective themselves. As for me, I think the idea we're talking about, running a larger 2 gauge wire fused at 150A from the battery to the alternator and disconnecting the "Main 2.0L" fusible link is a good one and is what I'm going to do when I do my install.

 

[TrickyT]

New type of fuse block available

I stopped by West Marine on my way home yesterday because I was seriously thinking of buying a 150A Megafuse ($13) and doing the experiment I proposed in post #101 above. I ended up not buying the Megafuse, but I did spot a new product from Blue Sea that I thought was pretty cool. It's called a Terminal Fuse Block; here's the URL: Terminal Fuse Block - Blue Sea Systems. There's a bunch of different fuse sizes available, from 30A - 300A: Terminal Fuse - Blue Sea Systems.

Since these fuses and fuse block are pretty compact, my thinking is that the fuse block could bolt directly to the battery terminal or battery connector and thereby avoid having to find a separate place to mount the Megafuse holder. Saves a little wiring too.

 

[Beowulf]

I think the idea we're talking about, running a larger 2 gauge wire fused at 150A from the battery to the alternator and disconnecting the "Main 2.0L" fusible link is a good one and is what I'm going to do when I do my install.

I just wanted to capture this as a summary for when I come back to this thread during my alternator upgrade project.

-B-

 

[NLXTACY]

I think at this point, what would make this thread really kick butt is a nice schematic showing before and after set ups. I thought I had it all figured out but this new discussion has me rethinking the project.

 

[TrickyT]

Sorry, no schematic. But the wiring is straight forward. Disconnect the ~7 gauge white wire where it connects to the Main 2.0L fusible link and tape up and secure the end so it won't short against anything. Then install a 150A fuse at or near the positive terminal of the battery and run a 2 gauge wire from the fuse down to the "B" terminal on the alternator (leave the existing wire lug also connected to the B terminal). That's it.

And credit where credit is due please: this was Photoman's idea! (See post #96)

 

[Beowulf]

And credit where credit is due please: this was Photoman's idea! (See post #96)

Noted.

-B-

 

[Photoman]

Sorry, no schematic. But the wiring is straight forward. Disconnect the ~7 gauge white wire where it connects to the Main 2.0L fusible link and tape up and secure the end so it won't short against anything. Then install a 150A fuse at or near the positive terminal of the battery and run a 2 gauge wire from the fuse down to the "B" terminal on the alternator (leave the existing wire lug also connected to the B terminal). That's it.

And credit where credit is due please: this was Photoman's idea! (See post #96)

Thanks for the credit.

There is a picture in post #22 of AM1 showing where the fusible link can be disconnected when I first proposed this way of doing the wiring.

One slight correction. The large white charging wire that runs from the alternator “B” post to AM1 is a ~6 gauge wire. The ~7 gauge wire goes from alternator “B” to the fuse panels.

Bill

 

[concretejungle]

i added a couple of good pics in post 67. that is basically what i did.

 

[landtank]

I've been asked to do this upgrade for someone so I'm way late in the game here. If this question has been asked and aswered I'm sorry and I'll delete this post from the thread.

I've worked on several European machines and have seen where they have run two separate fused lines to carry a large load. I'm not sure if it's a good practice or not, but is that something you guys have considered?

So basically leave everything intact but just add an addition line from the alternator to the battery with maybe a 80 amp fuse or whatever works out to compliment what is already there to provide the ability to carry the full 150amps to the battery.

And Bill, do you have any more kits?

 

[Photoman]

I have heard that it is possible to parallel fuses. The danger in my opinion is if one of either wires connections would get corroded then the other is asked to carry more of the load. Same thing if for some reason one fuse would fail except the other would have to carry the full load. I think if I were to try this, I would get another Toyota fusible link instead of a fuse and use the same size wire and length. That way both parallel legs would be equal and not unbalanced. Just my opinion.

Yes, I still have some more kits. PM or the email address here work if you need one.


Bill

 

[landtank]

I have heard that it is possible to parallel fuses. The danger in my opinion is if one of either wires connections would get corroded then the other is asked to carry more of the load. Same thing if for some reason one fuse would fail except the other would have to carry the full load. I think if I were to try this, I would get another Toyota fusible link instead of a fuse and use the same size wire and length. That way both parallel legs would be equal and not unbalanced. Just my opinion.

Yes, I still have some more kits. PM or the email address here work if you need one.


Bill

typically under high load if one blows then the other follows soon after. The confusing part is if you don't realize that there are two fuses. You end up replacing the blow fuse you know about only to have it last until the next high load and then it fails again.

Probably bets to stick with a single high amp line. Just thought I'd throw it out there and get some responses.

Rick

 

[TrickyT]

I'm curious as to the logic of the two parallel circuits. The downside is what you point out, plus the additional confusion for the user because it's a non-standard setup. What could the upside be, other than to keep the maximum wire diameter lower? Definitely it's not a common practice.

 

[landtank]

in my case we needed to run power through a track cable and the larger wire couldn't stand up to the constant flexing. The power aspects of our trucks is something that I've never taken the time to get to know intimately. I've actively avoided the need for a dual battery setup and have no love for big ass lights or high power stereo amps. But now I have someone who wants me to install one and I want to familiarize my self with the system to be confident that I am delivering what he expects.

So just through it out there to get some feed back.

 

[NLXTACY]

I have seen large output SINE converters that recommend going with (2) 4AWG cables as opposed to say (1) 1/0. For my own solution I preferred bring in ONE pair of 1/0 and call it a day. Now I can add anything I want in the future and as long as I'm not running something ridiculously high current, I will be fine.

 

[landtank]

I have seen large output SINE converters that recommend going with (2) 4AWG cables as opposed to say (1) 1/0.

there is actually a good reason for this. Most fires occure when there is a path to ground that isn't enough to cause a fuse to blow. I've actually seen this were a wire's insulation has chaffed enough to cause a high ohm short that created enough heat to combust but never trip the breaker.

This goes right into having a single high amp line from the alternator. While a dead short will always blow that fuse a high OHM one will just generate heat. The higher the amp of the fuse the greater the heat it can generate.

If you run two lines rated for half the amp draw then you have greater protection in these non dead short scenarios. And in a vibration situation this is the more common scenario you see.

 

[barCruiser]

Just thought I would add to the praise. I installed the 150 amp alt. last night, and was very impressed at how well the bracket is made, and how it fit perfectly. The install looks completely factory, and I couldn't be happier. Thanks again Bill.

 

[concretejungle]

Yep, but i will add that you really are not smarter than Bill for the install, so follow the directions to a tee or do it over and over again until you decide to follow the directions. Kinda like me.

EDIT: that wasn't directed at you barcruiser, just saying in general. His instructions are very accurate.