my JD 310C backhoe is draining battery while running. It continues to run so I don't think it would be the alternator. When I recharge battery andconnect the leads it sparks fire and I have to boost it with another battery. Thought the starter may have short in it but don't know how to check it. When battery was low after running a while I tried to restart and the started continued to drag slowly. Any help appreciated.
if its draining then it means its not recharging... so therefor it probably will be the alternator, but hey im no mechanic so :beatsme
I have had alternators that would charge while running, but had a bad diode and would discharge batteries when not running. One hint if this is the problem - if the alternator is warm after being shut off overnight this could be the problem. Hope it helps!
I will check this, Thanks
Bae216, first, welcome to HEF. Similar to advice I just gave in another thread, I'll mention this to you--many members browse the forums by looking at thread titles and reading the ones that interest them. My guess is that by titling a thread "bae216", you're going to miss out on somebody reading your question. I'll edit the thread title to give everybody else a clue of what's on your mind, and also move it to the backhoe forum.
You get a heavy spark when connecting the battery cable? Simple enough, if you suspect alternator, simply disconnect the battery wire connected to the alternator. If it no longer arcs when you connect cable at battery, there's your problem.
Thanks digger242j, I have just started using the site and learning my way around
The basic alternator test is with a volt-meter.:thumbsup Measure the battery voltage before cranking it. 12VDC is the nominal reading, it could be ~12.5 vdc. (If it gets below 8 or 9 volts things start shutting down and it will not restart.) Then when you crank it this voltage should INCREASE to at least 13.5VDC or some even charge as high as 14.5VDC You can get a VOM for as low as $20, but I would want one that costs at least $50. The good ones are over $200 but checking simple battery voltages does not have to be real accurate. If you have a 6 volt system, this is obviously all wrong. It sure sounds like a bad alternator or some loose wires to me. Bad ground connections to the frame can also cause charging issues. You can read from the battery posts to places on the frame to find this using voltage or resistance readings. A bad battery can damage an alternator or voltage regulator. (high current while not charging propery)
99% agree but a fully charged 12V battery should have 13.2V sitting (may be around 12.8V so you need to have at least 13.5V from the Alt to charge the battery, I would check this with all the lights and a/con ect on just to ensure you haven't dropped a phase of the Alt and only charging at 2/3's capacity top end charge as you say up to around 14.5V but this can cook your battery too, should be around 14.0V while it's not a sound method you can troubleshoot a faulty battery by checking the volts while cranking if it drops off and she won't start time for a new battery, another trick is to look at the fluid while cranking if a cell is bubbleing excessively while starting it's a bad battery also
In my opinion Bowen is more correct than Rare ss. A 12v automotive battery needs to be tested after sitting for at least 8 hrs or more after being fully charged. If healthy will read between 12.2 and 13.0 volts. May read above 13 volts emediately after a charge, but even a bad battery will read high emediately after a charge. When testing the voltage at the battery post with engine running, all lights, fans and everything electrical turned off, you should get 14 to 14.7 V. Less than 14 usually won't maintain your battery for the long term. If you get 14 or more with all electrical items off but are getting less with everything turned on, then you have too many lights or what ever for the capacity of your alternator.
have to agree to disagree, each cell on a battery gives 2.2V, hense a 6V (3 cell) battery will give you as much as 6.6V, a 12V (6 cells) 13.2V you must give the battery more charge than its capacity or it wont charge at the end of the day whatever works for you I guess
I don't see any disagreement at all. My numbers were only to present the general idea. The important part is see if the alternator increases the battery voltage when it's cranked. I have looked at the circuit for an alternator light and I still cannot understand how it works. I just decided it is a pretty smart light... If you measure the connected voltage from a battery charger using different amp settings you may see the voltage increase with higher settings. Most small chargers have a multi-tapped transformer inside. The 2amp setting may be only ~13 volts or whatever, etc. A small charger can help you determine if a battery is good based on the amp draw and charging time.
The exact formula for all of this is not always easy to make sense of. I own a 2007 Dodge Spinter. It's built by Mercedes Benz. You would think such a company could keep a battery charged. It's on it's third battery, second alternator and a new wiring harnes. I have installed a digital volt meter in the dash so I can watch whats happening. It charges at 13.9 to 14.0 volts. If it was not for a Battery Minder charger/desulfator that I purchased in 2010 and run on it at least once a month, I would have ruinned at least 6 batteries buy now. All other vehicles I have owned charge at 14.5 volts or there around. My 310D charges at 14.6 volts and the batteries show 12.8 volts after sitting idle for 2 weeks.
Temperature also comes into play because lead acid batteries require more voltage to charge when cold outside. In a constant current charging system it's not unusual to see readings in the 15 volt range.
It's been years since I have looked at a charging circuit but IIRC it is a voltage potential thing. When the engine is not running you have say 12 volts on one side of the lamp and zero volts on the other side which will make it light. When running (and charging) there is 12 volts on both sides of the lamp which is a zero voltage potential, or no power going to it at all.
If battery cable sparks when you touch it to post you have a short or something turned on. Make sure everything is off and connect a test light between cable and post. If light comes on you have a short. Start pulling fuses until light goes out and that is the where your short is. Pull wires from alternator to check test light because that system may not be fused. I would never leave a battery hooked up that sparked when connecting battery cable. Fire hazard. Starter will probabley not be fused either so pull wires. Also if a charged battery shows 10 or 8 volts with motor not running you have 1 or 2 cells shorted, get new battery. I have seen many a truck or tractor start well for years only charging 13 to 13.5 volts. In a perfect world you want 14 to 14.5. Good Luck
View attachment Alt_Light_580se-2.pdf This attached .pdf is my circuit as I understand it. One side of the light comes from the switch and the other side from the voltage regulator? maybe. (All I know is that this is a single wire from the box on the side of the alternator) I remember a time that my battery was charging at over 14 volts yet the light was on and indeed the alternator had a problem. (I wondered if the circuit was producing AC voltage to the battery because we damaged one battery in 3 months. ) The circuit is real simple and somehow this "potential" circuit works. My alternator light does not have a permanent connection to ground as some other warning lights do. It is real important to be sure your actual BULB is good. It should always come on when the key is switched on.:thumbsup
bae216 I found it was a short in the solehoid on the starter. Have not change it yet although moved the wire from shorting and it is staying charged and cranking probably. All you guys gave good advise and it was education at the least. Thanks for the replies:
Glad you got it figured out. It is always a good idea to post the problem like you did so we all learn. Welcome to the board.
Since bae got his problem sorted, i have a somewhat related and possibly amusing story. I had charging issues with a 6.0 this summer. It was an intermittent problem for almost 3 months. Thought maybe the UHF was killing the batteries when it sat for a couple days, but it did it a couple more times after we started turning the radio off. After we got to Idaho it would start kicking on the alternator light when you really poured some fuel on, but i didn't seem to be slipping. Next day it wouldn't start so with nothing better to do, i was told to figure it out. This whole deal was complicated by the fact we had one multi-meter and it was in the service truck and that was in WY. Managed to scrounge a meter and the alt was throwing out 13.8VDC with everything off. That was enough for me to start looking for a new alternator, but the bossman was unconvinced. I go to drive it over to where he's working and the abs light comes on. Alarm bells start going off over this massive coincidence. So, i try to roll up a window and i moves an inch or two. I throw the truck in reverse and get it back over by the shop before it dies. First time i've had to jump something to roll the windows up. Alternator light never did come on, must not have been a bright light.
Located this thread and it is very helpful. Allowed quick diagnostics for my '87 JD 310C. Thanks to all!