Starter and Alternator problems two questions

[ganderle]

Need some help here, accidently fried out the alternators by hooking the batteries up in series (12 volt 1500 amps). replaced the alternators. Now the glow plug wait lights don't go out. Question, is it likely a the glow plug relay or the glow plugs that would have been tanked? Second issue, I can turn the engine over (barely) but it binds down with fully charged batteries. Is it likely that my starter is also fried or is there a less obvious answer that is causing the problem. Help would be appreciated on this one.

Thanks

 

[dependable]

Stock batteries are hooked up in series, 24V, if modified to 12V, you could have fried several things, including glow plugs, glow plug controller, and starter, if cranked for more than briefly.

Hard to help you more than that without more info. Link below will answer a lot of questions for you if you are new to these trucks.

https://www.steelsoldiers.com/showthread.php?123199-CUCV-Helpful-Threads

 

[DOUBLE ALT]

I think you need someone who understands the electrical systems. A lot of questions to be answered.
A do you have 12 and 24 volt system ?
B. most likely you did short out a relay or burn a wire for the glow plugs.
C Do the glow plugs work ? Does it have a timer on it or is it manual only ?
D Have you looked at all the connections, both battery and all grounds for burn marks ? Better still take all of them loose and inspect, clean and reconnect.
E. Load check the batteries. Need a 1000 amp battery checker. Analog and Digital volt meter a must.
F. Does the starter smell like it is burned ? Does it show any signs of being too hot ? Look at the solenoids.
If you do not find it by now, say a big prayer. or two..
G

 

[ganderle]

I think you need someone who understands the electrical systems. A lot of questions to be answered.
A do you have 12 and 24 volt system ?
B. most likely you did short out a relay or burn a wire for the glow plugs.
C Do the glow plugs work ? Does it have a timer on it or is it manual only ?
D Have you looked at all the connections, both battery and all grounds for burn marks ? Better still take all of them loose and inspect, clean and reconnect.
E. Load check the batteries. Need a 1000 amp battery checker. Analog and Digital volt meter a must.
F. Does the starter smell like it is burned ? Does it show any signs of being too hot ? Look at the solenoids.
If you do not find it by now, say a big prayer. or two..
G

I inspected the wires and did not see any that looked fried. I corrected the problem before I tried cranking it. When I first put the cables on the terminals, the horn started going off so it was only a couple seconds. Once I realized what was going on, I disconnected it all and put it back right. With fully charged batteries, the starter moves but really doesn't crank. Since the wait light comes on for the glow plugs but does not go out, I am guessing I need to replace the relay for sure, BUT, I would think the starter would turn over much faster. I am not a mechanic and don't play one on TV. I will have a pro look at it. I don't want to be a parts changer if it is more easily diagnosed. Thanks for the quick response guys. I really appreciate it.

 

[doghead]

Was the truck in proper operating condition, prior to this ?

 

[ganderle]

Was the truck in proper operating condition, prior to this ?

Yes, but my alternator for Generator 1 was failing. Every couple weeks, I needed to charge the front battery. The other alternator light would intermittently come on when I first started the truck and drove for a few miles. The starter was in great shape though. If that is fried, I am thinking of having it changed for a 12 volt starter and be done with the 24 volt

 

[LT67]

Yes, but my alternator for Generator 1 was failing. Every couple weeks, I needed to charge the front battery. The other alternator light would intermittently come on when I first started the truck and drove for a few miles. The starter was in great shape though. If that is fried, I am thinking of having it changed for a 12 volt starter and be done with the 24 volt

Bear in mind that by changing to a 12v you will lose the cold weather starting power of the 24v system......

 

[porkysplace]

Yes, but my alternator for Generator 1 was failing. Every couple weeks, I needed to charge the front battery. The other alternator light would intermittently come on when I first started the truck and drove for a few miles. The starter was in great shape though. If that is fried, I am thinking of having it changed for a 12 volt starter and be done with the 24 volt

It's not a bad system once you understand it .

 

[gimpyrobb]

I find it hard to believe you would fry a 24v system by sending it 12v. I'd start with the fuseable links, as you'd have pulled more current through them than normal, but the other components, I doubt are bad.

 

[cucvrus]

24V vs 12V vs 6V.

Bear in mind that by changing to a 12v you will lose the cold weather starting power of the 24v system......

Being 24 volt does not make the vehicle start faster or better in cold climates. I had a 1942 GPW that was 6 volt and it started in dead of winter. The voltage of the system played no part in that. If the vehicle has good batteries and is properly maintained it will start in cold weather no matter what the voltage. A 6 volt with a good 6V or 12 volt with good 12 bolt and so on. Correct me if I am wrong. Open for correction.

 

[porkysplace]

Being 24 volt does not make the vehicle start faster or better in cold climates. I had a 1942 GPW that was 6 volt and it started in dead of winter. The voltage of the system played no part in that. If the vehicle has good batteries and is properly maintained it will start in cold weather no matter what the voltage. A 6 volt with a good 6V or 12 volt with good 12 bolt and so on. Correct me if I am wrong. Open for correction.

The GPW was also gas which tend to start better in the cold.

 

[DOUBLE ALT]

I somewhat agree that a lower voltage connection should not cause sparks. I believe it was a reverse of ground and battery.
A volt meter at the starter terminal post will tell a lot. A fully charged and good condition, 24 volt lead acid battery/s should read 25.2 volts with no load. With the starter engaged I would expect a reading close to 22/23 volts. If less check the cables both battery and grounds. No such thing as too many grounds. Changing to 12 volt not a good idea. I believe you have several other electrical parts that use 24 volts. Allison automatic transmissions and their computer use 24/28 volts on many Military vehicles. Basic lights and gauges come to mind too. Glow plugs may not glow. A good analog multi-meter is preferred because it will not rotate the numbers like a digital. Check starter voltage 1st. Good luck.

 

[MarcusOReallyus]

ganderle, are you still around?

Yes, you could have fried some diodes in your alternator. You might also have popped a fusible link or two. Work with us and we'll get you through this, but we can't help if you just go dark.

 

[DOUBLE ALT]

Higher voltage, is always better, than higher needed amperage to spin a motor/starter.
Look at some common uses. In your house they use 115 volt to turn on lights. They use 230 volts to turn on your ac compressor, your hot water heater, your stove, your dryer, all being electric.
Some reasons are much less voltage drop using higher voltage. 1/2 the wire size needed to to do the same work (12-to 24) . If you have common lower voltage from a worn or undercharged battery, you have more reserve with higher voltage.
Take 6.3 volt with 2 volt loss, you now have 4.3 volts to work with. 12.6 volts - 2 volts now have 10.6 volts.
So 26.2 volts - 2 you now have 24.2 volts usable. Electric vehicles are using 200 to 600 volts to the motors. Tesla is 375 volts. Very dangerous.
I Would prefer 36 volts for all. That also means a smaller and lighter battery.
The buried electric service to my transformer in my front yard is about 12,000 volts and converted to 230 volts to power my house.
Open to your thoughts.

 

[MarcusOReallyus]

This thread is about ganderle's alternator problems, not a general "what's the best voltage" discussion.

 

[gimpyrobb]

This thread is about ganderle's alternator problems, not a general "what's the best voltage" discussion.

Well, the OP did mention converting to 12v. If he does that and doesn't address his under-sized wires, he could catch fire. I see it as relevant imho.

 

[porkysplace]

Well, the OP did mention converting to 12v. If he does that and doesn't address his under-sized wires, he could catch fire. I see it as relevant imho.

The 120v/240v is irrelevant though , that's american thing , europe is pretty much all 240v.

 

[MarcusOReallyus]

Well, the OP did mention converting to 12v. If he does that and doesn't address his under-sized wires, he could catch fire. I see it as relevant imho.

If it were your thread and you were trying to get help with a problem, would you want to see it turn into a debate about which voltage is best? Or would you prefer to get help for the problem you posted?

 

[DOUBLE ALT]

Trying to help someone with their electrical problems may also include some extended education. A wiring diagram is a must if one is to dig into electrical trouble. I looked up a diagram of another MV and saw that it has a glow plug circuit board and relay. Easy test for glow plugs is to check voltage at the glow plugs. It shows 12 volts when turned on in this diagram I saw.
A quick test of all the glow plugs; If one or more, reads higher voltage, it can indicate it is not working. (because it has no load)
Then also check voltage at the starter as stated earlier.
I wish some had something to offer instead of criticism.

 

[MarcusOReallyus]

I wish some had something to offer instead of criticism.

There are people on this thread who know the system inside and out, and are just waiting for the OP to provide more info before providing guidance. Until he does, there's not much that can be done to help him, and a digression into the merits of various voltages does not help him.

He wouldn't be the first new poster here who registered, asked a question, made 3 or 4 posts, and was never heard from again. Sometimes that's because somebody jumps all over him and he's offended, and sometimes that's because his thread gets hijacked and he gives up in frustration because it doesn't look like his questions are being addressed.