24V engine in a 12V truck

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dieselcruiserhead

dieselcruiserhead

Joined
Jan 2, 2003
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OK, sorry to harp on this. I think this thread could potentially be a good "FAQ" if we get some good answers, all on one single thread. Please post how you would deal with the wiring, what you would replace & what you wouldn't. If you have already done it, I'd love to hear how you did it, what you would do again etc.

My best plan that is the easiest in my eyes, is using a converter. Something like a hig draw 50 amp model, something of high quality that is reliable. For example I ran a surepower 24/12V with 12V "memory" and it was awesome. Run everything off that including headlights. Am I insane?
 
Assuming you convert to 2 batteries to match the 24 volt starter and glow plugs, and use a 24 volt alternator, you then would have to run 24 volts through the converter you mention into the stock 12 volt fuse panel to power the rest of the truck.

I would be much more tempted to install a single wire 12 volt alternator in addition to the 24v, tap one battery to the fuse panel at 12 volts, then use the second alternator to keep the tapped battery juiced up.

The trouble with a converter is that you're pissing away so much energy, even with the expensive ones.

The third option is to trade for a 12 volt starter and glow plug system, and forget about 24 volts altogether.
 
dieselcruiserhead said:
For example I ran a surepower 24/12V with 12V "memory" and it was awesome. Run everything off that including headlights.
Click to expand...

I'm a total newb at all this, but por lo menos my BJ42 has 12v headlights, each one powered by each battery. Should be easy to wire that up so you don't draw so much current from the converter.

B
 
I guess it depends a lot where you live and what access you have to parts, etc. Since I live in a warm climate and I have the 12V parts needed, I'd just as soon convert a 24V engine to 12V to keep things simple.

Those living in cold climates swear by their 24V systems, but you can't help seeing questions here and there about how hard 24V winches are to come by, where do you get 24V bulbs and CD players, etc. But I am sure the starter's cranking power and a 24V winch's power prove the system's worth.

Split 12V / 24V systems are possible, even some cruisers have that from the factory, so why not. For the price of a converter you get to keep all the engine accessories and keep the rest of the vehicle 12V. We have a good dealer of a 24V to 12 V Solar Converter on this board (Greg_B)

The engine choice makes a big difference in what you'll do too. A 13BT with its 24V glow screen may be better kept 24V as it would be too expensive to convert to 12V. A 1HD-T from an 80 series would only need a 12V starter as the rest is already 12V, and this may only need a starter motor swap from a Hilux minitruck.

For Toyota diesel engines the parts that usually are voltage specific are
- starter
- glow plugs/glow screen
- engine shut off mechanism (fuel shut off or EDIC)
- alternator
- AC clutch (?)

The gauge senders AFAIK aren't voltage specific.

Dave
 
what engine is it andre... I thought about buying a 3bt and swaping over my 12v 3B items to make it 12v...
 
If you are putting a 24v motor in a 12 system, keep all the 12volt stuff you can and swap out the rest. This should be pretty easy however you did not mention what you are swapping with what in the way of motors or what series you are doing this on. speaking from experience you will have a lot easier time in the long run using basically a 12volt system, this is because of all the stuff you must convert or find in 24v such as bulbs radios accessories all that stuff. So it really gets down to what parts on the engine are 24volts and what you can do about it. If you are talking about a 13bt or 3b then the following are all I can think of that you need to swap:

glow plugs
EDIC
Alternator
Starter
maybe tach pickup (but doubtful)

That should be it right?

Am I missing somethign on this thread?

Michael
 
Andre,
here's what i did in my fj60 with a 24v 13bt in it.
i kept the motor 24v (starter, glowscreen, alternator, vsvs, etc...)
i kept everything but the motor from the fj60 12 v.
i have an additional racor 645 heated fuel filter and walbro fuel pump - both 24v

all the 12v appliances are run off a solarconverters 12/24-20 wired in eq mode. this allows for the 12v draw to exceed 20a if needed (although it exceeds the eq rate of the converter). I have an ammeter run through a shunt on the low side neg battery terminal that measures all current flowing in the system. with all accessories running (stereo, headlights on high, heater on high, wipers, etc...) i pull about 20a, right at the alternators capacity (25a @ 24v).

i would say that i'm running a fine line of electrical demand and a larger alt would be nice but my system is functional. add a winch, driving lights, offroad lights, etc... and you might be lacking a little. i'm pretty basic in this truck.... for me it was a financial option to swap out to 12v. for some bizarre reason the 12v parts are priced like they are gold when they really aren't anything fancy.

i'm watching to see how stone's experiment with wiring his solar converter up to make it both a step down and eq converter works. I think i'll do it once he gives it a no problem setup.

i don't think there are any other converters out there that beat the solarconverters. most "good" converters run in the 80-85% range where as the solar conv runs at 96%. i have one that runs my house for the past 5 years with no problems and i know the off grid world uses the most quality products for longevity and that converter is the only one that people really use for step down operations. G&S, as you know, sells the custom converter with the leds showing the state of eq and if the batteries are within 5% or less of charge. Pretty slick setup.

my .03

mike
 
i put my 13bt in a 12 volt 40. I kept only the starter as 24 volt, used a 12 volt alternator, and shutdown VSV from Greg and Sheldon. Used a heavy duty Series paralell solenoid switch and 2 batteries lots of cables/wires. Only running one of the glow screen elements with 12 volts.
 
See my best idea is about the same as stickboys. This is not for any specific project just "hypothetical" for the guy who posted on pirate about the Chevy 5.3 versus 1HD-T. Cool about the solar converter. I ran a surepower but was not relying on it. I think in a perfect world I would leave the truck as is and try to figure out a 24/12V system like the Australian diesel 80 series, best of both worlds. I sure loved 24V when I had it though. I run the most badass 12V system I have ever owned today and don't get me wrong it's great but even at 35 amps in 24V I was in heaven. Ever used your starter motor to get you up and over an obstacle?

Anywhoo....
 
Aussie spec 80's have a 12V starting system I believe. But I wonder if the 12V starter motor can be rewound for a higher power?

Dave
 
Mainer7 said:
i put my 13bt in a 12 volt 40. I kept only the starter as 24 volt, used a 12 volt alternator, and shutdown VSV from Greg and Sheldon. Used a heavy duty Series paralell solenoid switch and 2 batteries lots of cables/wires. Only running one of the glow screen elements with 12 volts.
Click to expand...

Mainer7 seems to be thinking along the same lines as me, I beleive most are reluctant to go with the 24 volt system due to availability of parts.

We used a 12 volt starter and alternator off a Toyota pickup and Supra, it seems like everthing else is working fine on 12 volts including the fuel solenoid.

The 13BT or 3B out of a BJ42(which I think have runn thier course) are the only units with some specific parts that are hard to change over to 12 volt. Even then most can be converted rather easily.

The 1HZ being 24 volt was a fairly simple change over with the alternator and starter being items we could find at the wreckers, I guess the Air condition pump and sytem would be another hurdle.


I would try and retain the 24 volt starter in the case of the 1HD-T or even our next 1HZ conversion, lotsa compression in the 1HZ motor (600PSI?).

The 1HD-T or FT are going to be lower compression engines due to the turbo..
 
Has anyone come up with the definitive answer on this?
I am swapping my 2H into an FJ60 and am trying to decide if the best system is to keep the engine 24V , add a solar converter and run everything else off it at 12V. I had originally planned to swap my HJ wiring harness in and run everything 24V. It might be easier to go the converter route though.
Would I be able to run the FJs 12V AC off the converter too?
 
My 24Volt BJ-42 has aftermarket AC running off of 12volts from my converter. Everything else is 24volts still.

I like Mainer's system. Many truckers had series/parallel switches back a few years ago so that they could start on 24volts and then everything else ran on 12volts. That's the ticket, IMHO.
 
I'm pondering this as well with the FJ45LV. The wiring on the LV is shot so I'll be rewiring it completely anyways. What are the thoughts of making it all 24v? The engine I'll be using will be a 3B from a Dyna or Coaster bus so probably 24v (if it's 12v then the truck will stay 12v).
 
dieseldog said:
Many truckers had series/parallel switches back a few years ago so that they could start on 24volts and then everything else ran on 12volts. That's the ticket, IMHO.
Click to expand...
I'm pretty simple when it comes to electrical. Can you explain how that would work.Only the starter would be 24V but I would need to change alternator, glows and EDIC to 12V then wouldn't I ? Would you flip a switch to 12V after starting with 24V or what?
Maybe the no brainer for me would be to just go ahead and swap wiring harnesses. I have all the 24V parts I need except my HJ didn't have AC.For the AC I guess I could run the 12V AC from the FJ off a converter or change the AC amplifier for a 24V one right?
 
Sounds more like he's running a dual battery 12V system, but with a trick relay that will combine both batteries for as long as the relay is engaged. The relay output is connected to the starter supply. I'm guessing though....
 
Latest guess on my system is that a starter relay activates a solenoid to combine the output of my 2 batteries to 24 volts for the starter. It's a one click start when it works. Everything else I've found or installed on my LC is 12 volts.

I live in a tropical country, but the one click start is so attractive that I'm trying to preserve my 24 volt starter.


Kalawang
 
Why even use an additional starter relay? Seems like you could run the starter wire to the special 24v combining relay which will deliver both 24V to the starter motor and to the starter's stock relay to kick it off. I still haven't found a diagram or picture of what the combining relay looks like, so I'm still speculating.
 
rutbeer said:
Why even use an additional starter relay? Seems like you could run the starter wire to the special 24v combining relay which will deliver both 24V to the starter motor and to the starter's stock relay to kick it off. I still haven't found a diagram or picture of what the combining relay looks like, so I'm still speculating.
Click to expand...


The relay is just a relay. The combining is done by the solenoid, as far as I understand it. I did use a direct connection for a couple of months sometime back, but have since returned to original wiring. Toyota designed this thing and I figure that they know better than I do.


Kalawang
 
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