M1009 Glow Plugs - 24 or 12 Volt?

[Recovry4x4]

My head hurts! I've often thought about moving the wire to the 12V block on the firewall but don't want to sacrifice the ability to slave. With that said, I'm know considering the merits of an SPDT knife switch to be able to go back to the resistor and slave it. Probably just killing brain cells thinking about it.

 

[doghead]

Kenny, unless your cucv goes dead often, it wont be an issue.

I recently had 2 bad glow plugs. If mine was not supplied with 12v, I would have had 6 more to change and a truck that would not start at all.

I just disconnected the red wire and taped it over. Made a new 10ga jumper with eye terminals on each end and installed it with a nice S shape. If I ever need to jump the cucv because it is stone dead, I will quickly switch back to the red wire.

You can still uses the cucv to jump start other stuff. It only effects jumping a dead cucv.

How's your head now!

 

[Recovry4x4]

Me head is just fine. I guess if its just a matter of swapping one wire in a pinch, should be no big deal. I never really thought about how easy it is to switch back and forth.

 

[ida34]

I was not advocating, nor did I recommend any other setup. However, the voltage present at the GP relay from the resistors in a stock military CUCV is 24 volts, the 60G (civy) glow plugs were designed to run on 12 volts only.

As always,
Your mileage may vary.

A little more to add to dogheads rebuttal. The resister will not drop voltage until it has a load. The load of a volt meter is not enough. The combined load of all 8 glow plugs will drop the voltage down to about 12 volts and it takes a second or two for the voltage to drop. This is the problem. If one glow plug goes bad it no longer draws any power. This caused the total voltage of the other plugs to go up. This then causes a snow ball effect as the voltage continued to increase with every glow plug that fails. The increase voltage is what takes out the plugs to after 3 or so the others fail real quick. To voltage must be tested at the glow plugs with the glow plugs on to get the proper picture of the actual voltage.

The only true 24 volt glow plugs are the ones for the humvee and they have a circular plug. The AC 13g, 60G and the wellmans are all 12 volt glow plugs.

 

[FMJ]

Thanks ida, it's called ohms law, E=IxR

 

[doghead]

Thanks ida, it's called ohms law, E=IxR

Oh great, now your offering legal advise!

 

[ida34]

Thanks ida, it's called ohms law, E=IxR

I was trying to keep math out of it but you had to go an ruin it.

 

[ida34]

On a similar note, I have posted this same information about three times in the last two weeks. Get on your job search Nazi.

 

[ccequipment]

I just went through this with my M1009, its all stock still using the 13G's. Of course they burnt out, there is one other diffrence between the 13g's and the 60g's acording to the NAPA specs, the 13G shows them being a 70watt glow plug and the 60g's 200 watt glow plug. has anyone heard of this, I just went back to the 13g's.

 

[FMJ]

Uh oh. . .

 

[ccequipment]

Yea, I decided to stick with the 70 watt 13g's so maybey they would be less likely to swelling when they get to much voltage when going bad. I thought the 200 watt 60g's may be more prone to swelling with to much voltage, but I am not a pro at this. I am sure someone has some insight. NAPA's specs could be wrong also.

 

[FMJ]

The nice thing about the 60g's is they are self limiting, so they are less prone to swelling.

But I agree, if the stock military gp system is working, leave it alone.

 

[doghead]

Here's a link to some Wellman data. http://www.wellmanautomotive.com/pdf/go50.pdf

The chart show the wellman tested was an 050, the only difference in the 050 and the 070 is the terminal size. It compares their GP to Bosch DS094 and AC 60G. You can see the the wellman does hold a flatter amp draw, over time and temperature, than the others. Too bad the AC13 is not listed in the data.

I was told the Wellman 070 GP was designed as a replacement to supply the government contract for GPs for cucvs.

 

[paraclete comes]

im thinking that i might just convert this by eliminating the 24 step down system. I dont have nor do i ever plan to us the slave cable jumping option. If this is the only draw back I think straight 12 volt to the glow plugs may be more beneficial in the long run for me.

am i missing any other potential drawbacks, anyone else come to this conclusion?

 

[tstone]

If you are considering converting to 12v, you want to use as large of a battery as possible like the stock 6VMF as the amp draw on the batery will be twice that of a 24v system. Most non military diesel vehicles use 2, 12 batteries in parallel to provide ample amp capicity for glow plugs and starting. Your other batery will only be necessary for the starter and minimal service to the fuse block. My preferance is to maintain original equipment whenever possible but this is not always conveinent.

 

[paraclete comes]

i think that may very well be the case here, leave it stock and hopefully i dont burn out glow plugs. thanks for the information

 

[cpf240]

Has anyone ever tried replacing the resistor pack with a solid state voltage regulator? Something that actually controlled its own output, rather then depending only on Ohm's law?

 

[doghead]

Has anyone ever tried replacing the resistor pack with a solid state voltage regulator? Something that actually controlled its own output, rather then depending only on Ohm's law?

The whole reason for the resistor bank is to make a normally 12 volt GP system compatible with the 24 volt NATO slave start.

You can simply rewire to 12 volts, rather than add a device to make 12 volts.

The only time rewiring the GP relay to 12 volts might hurt you is, if your front battery is completely dead or open celled, and your truck is cold. In that case, you could still just jump the front battery with a set of standard jumper cables.


There is no need to over complicate an already overly complicated system(for the NATO requirement).

 

[Star266]

There is yet different approach, using 24V and eliminating resistor .
Two glow plugs for each cylinder connected in series.
First eight mounted on special plate with eight threaded M10x1 holes.
That plate has to be insulated and mounted inside aluminum enclosure.
That enclosure is mounted on the top of AIR FILTER .
24V from relay connected to the plate .
From each glow plug FLAT connector to the glow plug inside cylinder.
This approach solves two problems : A – heat warms air intake – no waste.
B – connecting LED between each glow plug on the plate and 24V allow to monitor
Condition of each GP in the cylinder.
Someone may actually make a drawing. Monitoring is probably the most critical with this setup.

 

[doghead]

You better design a new controller card for that plan, the sock unit needs to see the voltage drop, to work correctly.

You could just duct the exhaust from a small jet engine into your intake...

Practical improvements are all thats needed. One wire, less than $2 and a few minutes time.