24v self education help please

[ThinkBig]

I looked around for a while and couldn't find too much info on this subject. I understand 12v very well and extremely capable with it. I am new to the 24v world and looking for some info to help "self teach" me the principals of automotive 24v. I even checked youtube and didn't find anything worthwhile. Heck, you can learn brain surgery on youtube, evidently not 24v automotive.
I have a Deuce and will be doing some mods and would like to do things right, instead of hit and miss, by guess and by gosh.
Thanks guys!

 

[Suprman]

Nothing different but higher voltage. You can use a power converter to get 12 volt from a 24 volt system if you want to run 12 volt accessories.

 

[gimpyrobb]

Yup

Everything is exactly the same, except how its stored.

 

[sue]

You want 12V pull from one battery, nothing big
But a cb or cell phone won’t hurt, seen big 12V
winches pulled on one battery for 12 V but engine
was running. And the
gentelman said his batteries were four years old?

 

[porkysplace]

Yup

Everything is exactly the same, except how its stored.

And when your working on it disconnect the batteries , because the arch's are a lot bigger than 12v and shorts tend to fry alternators.

 

[Crazyguyla]

Early PS Magazines covered the 24v system in great detail.

 

[ThinkBig]

Early PS Magazines covered the 24v system in great detail.

PS magazine?

 

[porkysplace]

PS magazine?

http://psmag.radionerds.com/index.php/Main_Page

 

[ThinkBig]

http://psmag.radionerds.com/index.php/Main_Page

I checked that out. VERY COOL! Thank you!

 

[MarcusOReallyus]

Nothing different but higher voltage.

Depends on what vehicle you are talking about. One of the big trucks? Yep, just higher voltages.


CUCV? The hybrid 12v/24v CUCV system is a different beast with some interesting quirks.

 

[jetman10]

I have a '67 M35a2 . My manual says the 24 volt system is pos ground ?

 

[Suprman]

I would use a multimeter to check and see.

 

[Guyfang]

I have a '67 M35a2 . My manual says the 24 volt system is pos ground ?

that I have to see. I am no expert on trucks, but have worked on many army trucks, going back to manufacturing dates in the 50's. All were Neg ground. This NOT to say the milatary never had Pos ground equipment. They did. Perfict example was the 45 KW Stewert and Steven gen set. Pos ground. We discovered the hard way, not reading the book is dumb. The first three 45 KW's we jumped off from MEP-006, (60 KW) the the wire harnes will burn with much fire and evil smelling smoke.

But out I think you need to go back and take another look.

 

[frank8003]

One demonstration of a 24 VDC battery system as against a 12 VDC system is that one can use the 24 VDC and weld with it. There is a difference there.
https://www.youtube.com/watch?v=b3vs7WCtRWE

When refurbishing cables and or changing batteries always clean and reinstall every ground connection.
In my Deuce I was refurbishing 48 year old electric connections so it was interesting.
Everything has to have a really good goeintah and goesoutah as per design.
My favorite ground to fix was found under the alternator.
Pictures for the General.

 

[Guyfang]

I used to have several wrenches that would have been nice additions to you welding pictures. But sadly, there was not much left of them. Never under estimate DC voltage.

 

[papakb]

jetman10, It's highly unusual for a U.S. military vehicle to have a positive ground system. If you were dealing with a foreign made or antique military vehicle maybe but anything in the M series should be negative ground. Slave cables and receptacles came into being with the M series and think of the fireworks you'd have if trucks had differing ground systems! Take a good look at your batteries and see if you can follow the leads and see which one runs to a bolt that's attached to the frame of the vehicle and that'll tell you whether or not it's positive or negative ground.

 

[dmetalmiki]

Do not ever ask for a jump start then!. There WILL be such a bang and flash you would not believe (or like to witness).
Your truck IS negative earth.

 

[snowtrac nome]

The big difference between 24 volt and 12 volt is the higher voltage requires les amperage to do the same work. This usually means smaller wires, but for some reason the military still uses wires large enough to handle 6 volt electrical systems.

 

[xGROMx]

You want 12V pull from one battery, nothing big
But a cb or cell phone won’t hurt, seen big 12V
winches pulled on one battery for 12 V but engine
was running. And the
gentelman said his batteries were four years old?

As Sue said, I have been doing this for a while on equipment and 5tons, no problem what so ever. Not really sure why so many people HAVE to have the convertors....Been used on buses for ages.