Is my M1009 24V or 12V?

[Rangerpig]

Hi, I am paranoid by nature, and the uncertainty of this question is bothering me. Is there an absolute way to tell that my vehicle is still 24V or did it get switched to 12 Volts?

The batteries are connected in series meaning 24v, but the Slave receptacle is unhooked, and the red wire that goes back into the vehicle and attaches to the bus bar in the back is unhooked.

Is there something that says, hey, look at me, I am still 24V?

Thank you!

 

[Barrman]

Do you have two alternators? Are they both hooked up? Where does the 10 gauge red wire on the back battery ground terminal go? Where does the power cable going to the starter motor come from?

 

[dougco1]

Volt meter is your friend. The M1009 was built with a 24Volt starting system and 24volt glow plug system. If PO rewired, you are basically on your own to determine what was altered or deleted.

 

[Rangerpig]

By voltmeter do you mean multimeter? I just picked one up a few days ago and have been studying up on it. Batteries push out 24 volts, not sure how to check starter. Turn it on and touch it with the multimeter?

 

[Rangerpig]

I do have two alternators and they are both hooked up. I have to go out and check the wires and see where they go. I replaced on a few months ago and the other more recently. BRB

 

[Rangerpig]

big thick red wire is going to the bar on the fire wall. I think that is the positive bus bar (what i read maybe?).

 

[MarcusOReallyus]

Just in case there's some confusion.... In a stock CUCV, the starter circuit is mostly 24v, and the GP circuit is partly 24v, and the rest is 12v. All of your lights, etc, are 12v.

So when you ask if it's 12v or 24v, the question has to be asked, what part of the beast are you talking about?

If your batteries are in series, you still have the stock starting system.

 

[WARWAG]

Some pictures of your engine compartment would help. Some of these vehicles have been pretty butchered because people don't understand how they work.

 

[Rangerpig]

Some pictures of your engine compartment would help. Some of these vehicles have been pretty butchered because people don't understand how they work.

Roger bud, I need to get home. I am away from home for a day or two. I will get back and let you know! The inside was horrible. I have a quick photo I took previous. Showing slave cable unhooked, and the rear bus bar being loose. I had no idea what was going on and finally got fed up and have since learned a great deal from the TM'S.

Sent from my SM-T560NU using Tapatalk

 

[Rangerpig]

Just in case there's some confusion.... In a stock CUCV, the starter circuit is mostly 24v, and the GP circuit is partly 24v, and the rest is 12v. All of your lights, etc, are 12v.

So when you ask if it's 12v or 24v, the question has to be asked, what part of the beast are you talking about?

If your batteries are in series, you still have the stock starting system.

I read there was a 12 volt conversion available. One that allows you to change it from24 bolts to 12 volts. When I asked if my truck was 12 or 24, that is what I was asking.

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[MarcusOReallyus]

I read there was a 12 volt conversion available. One that allows you to change it from24 bolts to 12 volts. When I asked if my truck was 12 or 24, that is what I was asking.

Okay, good. You are straight on the concepts. I had to ask because a lot of newcomers aren't. A hybrid 24/12vv system is a strange beast, and most people have never come across one.

Now to see what you really have once you have time to get some pics. :cheers:

 

[Castle Bravo]

...The M1009 was built with a 24Volt starting system and 24volt glow plug system...

While the glow plug system is fed with 24v, the glow plugs themselves are 12v and receive 12v when all is working correctly.

 

[Rangerpig]

WARWAG here are some photos I took. I have the batteries disconnected because I am working on her. They were wirred up in series. Positive to negative to positive to negative. The wires in the back along the firewall had me confused for a long time until I was able to study the TM and trace them back. Bottom disconnected wire goes to the bus bar in the back seat. The top disconnected wire was traced to the slave receptacle which pushes out zero amps.

 

[MarcusOReallyus]

Looks like your starter and GPs are stock. Hard to say what else might have been hacked.

I think those side terminal batteries might have force the previous owner to re-route some of the battery cabling so it would reach, so it looks a bit wonky, but since it's in series, it's 24v. The GP relay (which is NOT stock) is taking its feed from the resistor bank, so that's stock, too.

 

[Terracoma]

EDIT: Marcus beat me to it, but your truck appears to be wired as it was originally built, with the hybrid 24v/12v system, including the glow plug resistor bank.

The only non-CUCV wiring that I see is what appears to be an unfused 24v hot/ground (red/black) pair that is tapped into the bus bar(s), ziptied to the washer fluid lines across the firewall, and then drop down behind the master cylinder... Presumably towards the speedometer cable grommet and into the cabin.

 

[Barrman]

It looks like your slave port is what the big red wire that is not hooked to the buss bar.

Your drivers side alternator belt is too thin. I couldn't tell if it was the proper belt that has just worn down that way or if it started off as the wrong size belt.

 

[jnlperformance]

1)use a multimeter / voltmeter

2)there should be two thick red wires (8-10 gauge) on the post terminals on the passenger side (24v) gen. the post terminal with an extra red wire thats around a 12 gauge wire is the 24v post. the other red wire thats 8-10 gauge is the ground terminal / 12v terminal.

3)checking is very simple. turn the truck on, idle. take the hot/red probe and put on the (2 wire) post which should be the 24v post on passenger gen. then ground the other probe out on either metal or the primary ground post on the battery bank. if it reads 26v @ idle then your ride is still 12/24v. if it reads 14v then it may have been converted and / or there is a wiring issue somewhere if its reading something like 15,16,18 volts...

4) check 12v post on pass gen. just to be certian about wiring issues. it should read 14v @ idle. if the ground/12v post reads less than 12v then there is a major wiring issue somewhere, and the system is still 12/24.



to clarify again, because you can get a nice shock if you slip... always connect hot first, then ground second. especially when reading voltages and amps.

one post should read 26v @ idle, the other 14v @ idle. any other readings indicate an issue.

also, if it had been converted then the gound / 12v post on the passenger gen should be a ground and not recieving 14v from the driver side gen.

AND... on the passenger gen... the post with a large red wire (8-10 gauge wire) AND a smaller 12 gauge wire IS the 24v post. the post with just a singe large red (8-10 gauge) wire is the 12v post on the passenger side which recieves 12v from the driver side gen, or if its on the driver side, the same post serves as the ground.

by what ive read and by looking at piks it would seem to me the system is still 12/24 hybrid. keep it. far superior... and cheaper.

 

[jnlperformance]

yes by looking @ your piks a bit closer... it looks to still be 12/24v.

you can also test by taking volt meter to TOP junction block and testing it. it should be 24v. the bottom JB is common ground.

you can tell by looking at the GlowPlug resistor block. it should be connected to top JB, which is 24v, voltage passes thru resistor block (which is the black thing on your firewall) and the resistor block brings the voltage down from 24 to 12v post resistor block.

 

[spankybear]

Volt meter is your friend. The M1009 was built with a 24Volt starting system and 24volt glow plug system. If PO rewired, you are basically on your own to determine what was altered or deleted.

The glow plug system is a trap. While its a "24 volt" system you do not want more than 15 volts applied to a glow plug. The 2 dropping resistors drop the voltage to around 14 volts +/- with all 8 glow plugs in working order. If you have 3 or more burned out glow plugs your voltage will go up and you will have a very good chance of bulging the tip of the glow plugs. Even with the newer design glow plugs. And it seems to be always one of the harder to get 2 rear ones. It's a PIA even if you have the extractor tool.

The reason I bring this up was someone I knew thought the resistors where bad as he measured the open voltage of 24 volts at the resistor. He then just wired the system direct to the 24 volt buss bar. HE smoked the system.

 

[MarcusOReallyus]

voltage passes thru resistor block (which is the black thing on your firewall) and the resistor block brings the voltage down from 24 to 12v post resistor block.

Yes, but only when the GPs are operating. If there is no current flowing (relay is not engaged), you'll see 24v at the top of the relay, after the resistor.