another 12/24volt ?

[bear76]

Hello, new member here.

I have a 84' m1009. Bodys great only 49k but has other issues. I'll post each as one as I get ready to fix them, if I need help.

First question I have regards 12v/24v. I was thinking of keeping it 24/12v for now and later just running all 12 volt. My problem is that my truck was missing one of the alt. (the other was removed, but came with the truck). I have read that a stock chevy alt would fit but I need the ground removed from it. Could someone please explain the process? Do I just not ground it? Or am I completely wrong in my understanding of this.

Thanks

 

[OPCOM]

It's a different model of alternator that does not have the negative side internally grounded. I was let to believe it is the rectifier inside that is different, having a gound wire coming out instead of just internally grounding.

 

[Zinlu]

Aye that's the difference. 14v comes out of the lead alternator, goes to charge the first battery, and to the ground on the second alternator(there's where the need for isolated grounds comes in). Since the second alternator has 14v coming in, it basically adds its own 14v to that making 28v to charge the back battery.

I can't remember how much more expensive the isolated ground alternators are as compared to a regular one, but the NAPA here locally has the 12v starters that will work on the 6.2 for $120. Figure maybe another $30 for cables, etc and I'd be lookin at ~$150 for the 12v conversion, v/s what an alternator would cost. If you've got any alternator/starter rebuild shops around, you might try them, also. It's funny what some of the older shops might have "laying around" in the junkpile.

You'd probably want to check with an expert first, but having a regular internally grounded alternator as the first in the circuit might work. If the second alternator goes out though, it won't leave ya much in the way of options.

 

[n1vbn]

Which alternator is missing? The drivers side (number 1 alternator) is grounded to the engine block which is a black wire. As the vehicle comes from Chevy both alternators are isolated ground alts. but only the number two passenger side REQUIRES an isloated ground alt. The passenger side alt receives 14 volts from the passenger side alt and adds 14 volts to it to charge the second battery This means you can use a standard alt on the drivers side but be advised there is a good possibility you will find a ground isolated alt on a rebuilders shelf and he may not even know it.

I would leave the system stock. This gives you the capability to slave start other military vehicles. The reason there is a resistance block behind the air cleaner feeding the glow plug relay is so if the batteries are totally dead you plug a slave cable into your vehicle and then a jump vehicle and you instanly have power at the glow plugs thru the 24 volt resitance block which drops the voltage down to about 12 volts for the glow plugs.

The CUCV Delco 2 alternator system uses 100 amp Delco 27-S1 isolated ground alternators but only number two demands the isolatedf ground.

It is a simple system once you understand it properly that works well. I retain my M-1009 in stock electrical configuration and it works very well with no problems.

 

[IBEZKUM]

Here's, the alternator I got from NAPA, Works Great!!
My truck was missing the drivers side ALT. and the Starter,
Not cheap, But Both work very well!!

 

[IBEZKUM]

OOP'S SORRY, MY MISTAKE IT WAS THE PASSENGER SIDE ALTERNATOR!!!
Here's the starter pic if you want it!!

 

[bear76]

Thank you for all the responces so far. I dont know which alt I have, it was in the back seat. I might just convert to 12v because the glow plug relay is missing too. I have the instuctions for converting but are there any tips I should know before starting?

Thank you.

 

[bear76]

I hate to sound ungrateful but how come some just did'nt say "the two alts are run in series". It took me two days to recognize this, but now I do.
Anyone have a spare alt hanging around or have line on a good price somewhere?

Thanks.

 

[MATT]

I covert our trucks to a 12v manual glow plug system that uses a momentary switch and comes off one battery. It has worked great for 5+ years with no problems. Some folks say that coming off one battery is bad but glow plugs stay on for very little time. I use AC Delco 60g glow plugs from Napa and remove the resistor block and replace the glow plug solenoid, install a momemtary switch and wal-lah.

 

[1956_4x4]

I hate to sound ungrateful but how come some just did'nt say "the two alts are run in series". It took me two days to recognize this, but now I do.
Anyone have a spare alt hanging around or have line on a good price somewhere?

Thanks.

Some of us might have thought you had looked at the schematic in the tech manual section to figure out the series issue. Pretty simple once you have that part of the system down. You might look on ebay for an alternator, DB Electronics has been a good vendor for me.

Does this mean you have decided to stay 24 volt or are you still looking at 12 volt? Hope I was able to answer your questions over on CK5.


Smitty

 

[bear76]

Hey Smitty, I thaught that was you. I'm still learning where things are around here and did not know about the tech manual section. I have to weigh the price factor between the two. I'm missing one alt and a GP resister (so far). For 12v I need a starter and maybe a new alt.

Thanks again.

 

[1956_4x4]

Are you talking about the two resistors mounted on the fire wall, behind the engine?

Smitty

 

[bear76]

Yes, the Glow plug resistor. But I thought it's only one big one, right behind the air filter on the firewall.

 

[1956_4x4]

Yes, the Glow plug resistor. But I thought it's only one big one, right behind the air filter on the firewall.

It cost me just over $100 for a new 12-volt gear reduction starter. The rest was just a couple of hours for the conversion. This conversion works for me because I will never need to use the NATO plug. It also eliminated some equipment that could fail in the system (wiring, resistors, and an alternator).

Now, if you decide to stay with the 12/24 system, you can have the resistors (and cover) that I removed from my truck. You pick up the tab on the shipping and they're yours.

Smitty

 

[bear76]

Thanks agian Smitty.
After sleeping on it, I've decided to go 12v. I like the pricing on the DB elec. starers and you said in another post you were happy with what you got, so I'll do the same. I'll have my alt checked at the local napa store and go from there. If it checks out great, If not I'll go to the junk yard and look for an alt there.

Thanks.

 

[mangus580]

If it doesnt check out to be good, I would suggest finding a shop to rebuild it. The alts in the CUCV are the 'large' frame alternator, and put out around 100 amps. The standard alt for that year was something along the lines of a 63 amp, and may not fit in the bracket you have.

 

[bear76]

Thanks for the info magnus. I'll try to find a local rebuild place.

 

[1956_4x4]

Thanks agian Smitty.
After sleeping on it, I've decided to go 12v. I like the pricing on the DB elec. starers and you said in another post you were happy with what you got, so I'll do the same. I'll have my alt checked at the local napa store and go from there. If it checks out great, If not I'll go to the junk yard and look for an alt there.

Thanks.

When NAPA checks out the alternator, be sure to let them know you have an external ground.

Smitty

 

[bear76]

Sure thing.

 

[bear76]

Well the alt is no good. Just ordered an alt for a mid 80's Cadi. Housing looks the same, but it's an internal ground. It's 100amp, napa part #213-4205. It'll be in about an hour and I'll match them up then.