Cucv m1010 resistors check and replace / bypass?

[Sergey G]

I have a concern that my glow plugs fried due to malfunction of resistors. The way I checked resistors was supplying 24 v to them and getting the same 24 v on the other end which goes to glow plug switch. I have an extra used resistors which showed 24 v on the out end as well. Does that mean they both are out of order??? Theoretically it should give 12 v on the out end, correct? Except for excess drain on the battery why cannot I just go directly battery -glow plug switch 12v ?? The other confusion that I have are those resistors purely for glow plugs?? Then how how does the entire light system getting 12v if I remove resistors or it gets their 12v somewhere else? I had in mind that only starter and burner are on 24v and everything else is 12 v. So I,m kind of confused. Thanks in advance

 

[TGP (IL)]

Your resistors are probably fine.
You have to "load" the resistors for them to drop
Voltage.

So with all eight glow plugs working you will see 12-14 Volts
At the relay.
As one plug fails the voltage comes up (rises) causing a domino failure
Effect on the plugs.

Read the sticky's top of CUCV forum.
Tom

 

[MarcusOReallyus]

Check this out, Sergey: http://www.steelsoldiers.com/showth...plug-blowout&p=1942848&viewfull=1#post1942848

 

[Sergey G]

Check this out, Sergey: http://www.steelsoldiers.com/showth...plug-blowout&p=1942848&viewfull=1#post1942848

Thank you, that clears out . But isn't there a way to check resistors with a ohmmeter? I had an issue where my resistors were giving burnt wiring smell , almost smoked few times. I' m concerned they are functioning not properly under load. Just want to avoid burning bright new glow plugs.

 

[Sergey G]

Thank you. Is there a way to check resistors with ohmmeter? Mines were also smoking several times really bad, so I m seriously thinking of resistors bypass.

 

[firefox]

If you are in an enviroment where there are oher Military Vehicles that
are equiped with the NATO cable hookup, then it would be a bad idea
to eliminate the resistors. They are there so that you can jump start your
vehicle from another NATO cable equiped vehicle.

 

[TGP (IL)]

I have read that comment before.
Can you explain to me why that would be a problem?

I mean when you plug in the donor vehicle to jump yours
The current will back feed to the batteries and light the Glow plugs Right?
Tom

 

[firefox]

Not sure of the details, but if the batteries are toast you can still get the engine started
and be on your way. Very desirable when your taking fire. Especially when it is from your
wife....and its 30 degrees below freezing...

 

[MarcusOReallyus]

Thank you. Is there a way to check resistors with ohmmeter? Mines were also smoking several times really bad, so I m seriously thinking of resistors bypass.

Yes, there is. I don't recall the correct value, but it's listed in the TM.

 

[Sergey G]

What about putting in a modern type 24-12 v converter 300watt so I have steady 12v?. I still do not get the engineering idea if this ballast resistors being 24 v and dropping it to 12 under load - glow plug switch 12v, gp 12v. I imagine it should give 12 v right when it reaches gP switch, otherwise there is always a room for burning something in That chan.

 

[richingalveston]

The glow plugs pull some where between 750 and 1000 watts of power.

It would take a larger converter and the resistor is more reliable.

If you do not need to jump the truck from another 24 volt truck, just bypass the resistor.

If you have another nato truck and you want the jump start ability then leave it stock.

any oil on the resistor will cause it to smoke but normally it does not hurt it.

I got rid of mine because I have no way or plans to jump it from another nato truck.

rich

 

[MarcusOReallyus]

If you do not need to jump the truck from another 24 volt truck, just bypass the resistor.

I still do not get the engineering idea if this ballast resistors being 24 v and dropping it to 12 under load

I agree with Rich. If you don't need to jump from NATO vehicles, bypass them. If you do, leave it stock.


Either way, just trust us that it really does work that way, and it works just fine.

 

[Sergey G]

Thanks, guys, no need to jump any. Then bypass. The proper way to connect it would be the negative of the battery closest to the firewall, right? Fusible link would be a must?

 

[richingalveston]

Disconnect the wire that goes from the 24V block on fire wall above heater fan and disconnect the same wire from the resistor. The wire on the other side of the resistor needs to be removed and reconnected with a fusable link to the 12 volt terminal block that is next to the glow plug relay. you can leave the resistor in place or remove it, once disconnected it is your choice.

no need to run another wire from the battery to the glow plug relay. just connect it to the 12 volt source next to the relay. The wire that connects the 12 volt terminal block to the battery is large enough to handle the glow plugs.

 

[Sergey G]

Disconnect the wire that goes from the 24V block on fire wall above heater fan and disconnect the same wire from the resistor. The wire on the other side of the resistor needs to be removed and reconnected with a fusable link to the 12 volt terminal block that is next to the glow plug relay. you can leave the resistor in place or remove it, once disconnected it is your choice.

no need to run another wire from the battery to the glow plug relay. just connect it to the 12 volt source next to the relay. The wire that connects the 12 volt terminal block to the battery is large enough to handle the glow plugs.

Super!����thanks!!

 

[MarcusOReallyus]

Rich is describing the standard way it's done, and it's just fine. There's another way to do it it in the resistor bypass sticky, for your consideration. Look for the muddy resistor bypass.

 

[richingalveston]

For those wanting to keep the resistor for jump starts, it takes about one minute to connect it when it is needed. just leave the wires connected to resistor leave the resistor in place and just disconnect it from the 24V terminal and tape it up. Disconnect it from the glow plug relay and tape it up. make new wire between glow plug relay and 12 volt terminal block with fusable link.


When you need it just disconnect the 12volt wire and reconnect the resistor and jump away.

This way you avoid the cascade issue for 99% of the time but still have the 24volt jump capability the less than 1% of the time when you need it.

Very simple solution.

Rich

 

[Recovry4x4]

For those wanting to keep the resistor for jump starts, it takes about one minute to connect it when it is needed. just leave the wires connected to resistor leave the resistor in place and just disconnect it from the 24V terminal and tape it up. Disconnect it from the glow plug relay and tape it up. make new wire between glow plug relay and 12 volt terminal block with fusable link.


When you need it just disconnect the 12volt wire and reconnect the resistor and jump away.

This way you avoid the cascade issue for 99% of the time but still have the 24volt jump capability the less than 1% of the time when you need it.

Very simple solution.

Rich

This is how I do mine. Works great.

 

[TGP (IL)]

So Obviously No One wants to explain why you have to have the resistor's working
To jump start from another MV via slave cable.

I say BS!

Truck A is dead, plug truck B into truck A via slave cable.

Current flows through cable to 24V buss bar, down to the Starter.
It also back feeds to the batteries supplying power at the 12V junction block at
The firewall, thus feeding the rest of the trucks 12V needs.

Otherwise you would have No current to energize the Starter relay or the IP.

So makes No difference if the GP are fed through the resistor's or the 12V block.

IMO, the only reason for the resistor block is to draw equally from both Batteries.

So what am I missing here?

Tom

 

[richingalveston]

if your front battery has a dead short or dead, you have no 12 volts until your alts start producing. thus you cant heat glow plugs.

if the front battery is just dead, it will produce 12 volts with the 24 running through it so the IP will open. IF the front battery is completely shorted or gone, I don't think the ip will open until alt turns fast enough and I am not sure if the starter will do that.


There is nothing in the system to convert the 24volts to 12 other than the front battery if dead and not bad. other than an alt providing it or the front battery providing it or resistor. you can't get the 12 volts on the glow plugs prior to cranking

This is the reason for the resistor.

it does help balance the batteries upon start up but that is just a secondary benefit.

also a dead front battery will not produce the large amp load for the glow plugs with just 24volts running through it.