How to Jump Start CUCV

[jplace1011]

I feel really silly asking this, but I’d rather ask a silly question than make a huge mistake. I’m a new owner and still learning; I have a 1985 CUCV and I realized I left the floodlight on after it was parked. I haven’t tried to start it yet, but if I do I want to ask if there’s a particular way to jump start it? Since it’s a 24v system I’m thinking it requires a certain way?

Thank You for any and all help!


Sent from my iPhone using Tapatalk

 

[Keith_J]

CUCVs, like all other military equipment, have jump starting equipment. Called the NATO port, it is a coaxial connection I the upper right of the grill. You need another running piece of equipment with a set of NATO cables.

CUCVs can also use regular jumper cables. Just connect correctly. If you only discharged the front battery through a single 12 volt load AND the back battery is good, you can just jump the front battery.

If both batteries are discharged, you need a third vehicle and another set of cables. Make sure no vehicle touches another.

 

[royalflush55]

If jump starting directly to one or both batteries connect jumper cables positive to positive and negative to negative Just like you normally would if 12 volt system.

 

[98G]

I feel really silly asking this, but I’d rather ask a silly question than make a huge mistake. I’m a new owner and still learning; I have a 1985 CUCV and I realized I left the floodlight on after it was parked. I haven’t tried to start it yet, but if I do I want to ask if there’s a particular way to jump start it? Since it’s a 24v system I’m thinking it requires a certain way?

Thank You for any and all help!


Sent from my iPhone using Tapatalk

What are you going to jump it from?

What equipment do you have available?

 

[jplace1011]

What are you going to jump it from?

What equipment do you have available?

Hi There, I was thinking of jumping it from my wife’s Jeep using results jumper cables attached to the front battery of the CUCV. Thanks for any input.


Sent from my iPhone using Tapatalk

 

[jplace1011]

CUCVs, like all other military equipment, have jump starting equipment. Called the NATO port, it is a coaxial connection I the upper right of the grill. You need another running piece of equipment with a set of NATO cables.

CUCVs can also use regular jumper cables. Just connect correctly. If you only discharged the front battery through a single 12 volt load AND the back battery is good, you can just jump the front battery.

If both batteries are discharged, you need a third vehicle and another set of cables. Make sure no vehicle touches another.

Hi Keith_J This is great advice thank you very much sir.


Sent from my iPhone using Tapatalk

 

[jplace1011]

If jump starting directly to one or both batteries connect jumper cables positive to positive and negative to negative Just like you normally would if 12 volt system.

Hi Royal, this good advice. Thank you and have a great day sir.


Sent from my iPhone using Tapatalk

 

[98G]

Hi There, I was thinking of jumping it from my wife’s Jeep using results jumper cables attached to the front battery of the CUCV. Thanks for any input.


Sent from my iPhone using Tapatalk

Sounds reasonable. The assumption is that just one battery on the cucv is discharged.

It's important to ground to the negative post on the battery, as mentioned above.

Let us know how it goes.

 

[jplace1011]

Sounds reasonable. The assumption is that just one battery on the cucv is discharged.

It's important to ground to the negative post on the battery, as mentioned above.

Let us know how it goes.

I ended up being able to start the Blazer up with no problems. I’m assuming the flood light wasn’t on for very long.

Still thank you all for the advice on how to jump start. I now know how to do that!


Sent from my iPhone using Tapatalk

 

[SomeNewGuy]

Hopefully this isnt too much of a necro, but I didnt feel my question worthy of another thread when this is already here.

For clarity, I understand that is both batteries are dead you need 2 other cars, one to jump each battery.

Assuming you are on the side of the road, and only one person has stopped to help, would it not be possible to jump the batteries by connecting to the pos on the front battery and neg on the second battery? Then just wait longer to get a charge into both?

 

[Mullaney]

Hopefully this isnt too much of a necro, but I didnt feel my question worthy of another thread when this is already here.

For clarity, I understand that is both batteries are dead you need 2 other cars, one to jump each battery.

Assuming you are on the side of the road, and only one person has stopped to help, would it not be possible to jump the batteries by connecting to the pos on the front battery and neg on the second battery? Then just wait longer to get a charge into both?

.
No. Affix your cables to one battery. One to positive, one to negative. Ignore the idea that you are attempting to charge & crank a 24v system. Put 12v into battery one, see if it cranks. If everything is still dead - you may have more than just a low battery problem.

 

[SomeNewGuy]

.
No. Affix your cables to one battery. One to positive, one to negative. Ignore the idea that you are attempting to charge & crank a 24v system. Put 12v into battery one, see if it cranks. If everything is still dead - you may have more than just a low battery problem.

So my understanding of the system is that the resistance in the plugs ect is what drops the voltage for the glow plugs down to 12v... if this is correct wouldnt starting from only one battery not work as there wouldnt be enough voltage, i.e. the 12v starting would be even lower due to the resistance?

 

[98G]

So my understanding of the system is that the resistance in the plugs ect is what drops the voltage for the glow plugs down to 12v... if this is correct wouldnt starting from only one battery not work as there wouldnt be enough voltage, i.e. the 12v starting would be even lower due to the resistance?

In real world situations, likely one battery is more dead than the other, so it's worth attempting to jump one battery from a 12v vehicle.

If you're going to attempt to charge both of the cucv's batteries, instead of wiring them together just charge one for 10 min or so and then attempt to start by jumping the other one.

 

[SomeNewGuy]

Much appriciated for the info gents. Just wanna know what to do before I am in the situation.

 

[nyoffroad]

I'm not trying to be a wise guy but the best thing you can do is avoid having to jump start it at all. Load test your batteries and clean all connections and keep them tight. Keep the alt. belts tight too. And don't forget the connection on the starter itself. A little time and work this time of year will keep you from freezing and cussing a lot in the winter!

 

[Mullaney]

I'm not trying to be a wise guy but the best thing you can do is avoid having to jump start it at all. Load test your batteries and clean all connections and keep them tight. Keep the alt. belts tight too. And don't forget the connection on the starter itself. A little time and work this time of year will keep you from freezing and cussing a lot in the winter!

.
Smart for sure nyoffroad !

Cold and it needs to be raining too... You need to be wearing better than normal clothes too. Oh, and don't forget the rubber mat that you roll up and throw in the back of the truck - just in case of such a calamity - was left in the garage. So, yeah cold and wet and a little miserable when it happens is pretty normal.

A spot or two of electrical contact grease on the batteries and cables and the connection to the alternator and starter will make life easier. That stuff is conductive and made specifically for the job.

 

[Mainsail]

Has anyone tried those little jump boxes? I was thinking of getting a pair of them for the glove box- so at least I'd have some capability to jump both batteries once or the dead battery twice.

But if they don't work well, then I won't bother.

 

[Mullaney]

Has anyone tried those little jump boxes? I was thinking of getting a pair of them for the glove box- so at least I'd have some capability to jump both batteries once or the dead battery twice.

But if they don't work well, then I won't bother.

.
I have one that I got from Interstate Battery several years.

Have a F600 with a small Cummins with a 5 speed manual and split axle. Truck has a 12 volt system with a pair of batteries. Before I FINALLY FOUND the drain on the batteries (something in the Maxxon lift gate) I would occasionally find "no go go juice" . The Cummins would crank in maybe a full revolution on a normal day. Using the little jumper box would give me one start.

It worked well. Perfect - no - but it would get me cranked.

 

[cucvrus]

The front battery is usually the only one that is dead when a 12 v item is left on. So standard jumping on the front battery of the CUCV is the same as a normal vehicle. DO NOT try that with the rear battery. Also keep in mind when you do the glow plug resistor bypass you have now made the front battery and Gen 1 do all the glow plug work that the proven multi million dollar design was doing along as designed from both batteries and both Gen 1 & 2. Do as you will Good Luck. And say what you will. You will.

 

[Keith_J]

Back when the M35s were being auctioned by GL, I helped a friend liberate one with dead batteries using my car and a set of jumper cables, one battery at a time.

I had to fix the brakes on the vehicle, used a little low air pressure on the master cylinder to set the wheel cylinder cups flat. In that time, I had several retirees tell me that was a 24 volt truck and my car was only 12 volts.

It started on the first attempt. I measured each battery, hedging a bet one of the two 6TLs would be good. My car has a 120 amp alternator so disconnecting the truck batteries and charging them in parallel could be done in an hour or so.