JD 310SG battery leaking current

[Armymutt]

Went out tonight to start my new-to-me backhoe. It was completely dead. I checked the battery voltage - 3V. Charged it for the past 5 hours and hooked up a test lamp. Sure enough, the light is on - not super bright, but a glow. I pulled every fuse and relay under the cover on the dash. I also pulled the ignition switch because the key hole is worn and it's hard to tell if it is in off or on. Still have a glow. Multimeter is showing 0.00 amps between the negative post and the cable, and battery voltage across the same location. Don't know if that is significant. I'm a veterinarian and it's been a long time since my auto shop days. Not sure where to go from here. I think the business that owned it never realized it had the leak because they ran it almost daily. The last time I was on it was a week ago. Do these just naturally draw voltage like a modern car and just need to put it on a battery tender?

 

[Delmer]

The alternator is still hooked to the + battery terminal, if the diodes are leaking even a tiny bit, that will drain the battery over a week. Or the battery is discharging on it's own. I'd leave the charger on there for a day, then remove and leave the ground cable off the battery until you use it next time, then see if it starts or not. And then get a new battery, or look into the alternator more.

0.00 amps, I don't trust. The glowing test lamp, I trust. I suppose it's not that hard to remove the big b+ terminal wire at the alternator and see if the lamp goes out, if you don't want to wait.

 

[Armymutt]

Doesn't appear to be the alternator. Took the B cable off and no change to the light.

 

[Ronsii]

I would think a 310SG would have a master disconnect.... if not then put one in it

 

[mg2361]

Multimeter is showing 0.00 amps between the negative post and the cable, and battery voltage across the same location.

Serial number would help. Ignore voltage when checking for battery drain. It is normal for those machines to draw up to 0.025 A (25 mA). But absolutely no more than that. 25 mA will not light a test light. If you are lighting a light then there is too much draw. Since you pulled fuses, disconnected the ignition switch and the alt battery terminal, try (one at a time) disconnecting the other alternator connections, unplugging the neutral start relay and disconnecting the accessory relay and see if the drain goes away. Also, if there is the numbers 105 or 195 stamped on the metal of your ignition switch, replace it. Those switches are known for shorting out.

A battery disconnect is an option on those machines and if you have it, it will be located on the left side engine compartment mounted to the main frame.

 

[Armymutt]

The serial number is T0310SG915996. I'm pretty sure I pulled the two relays you mention last night. If they are under the dash cover, I pulled them. I also pulled a relay that is under the gauge panel - mounted to the left side. I'll try disconnecting the other wires on the alternator after I finish playing teacher today. Ignition switch has no numbers stamped on it. I looked up a battery disconnect switch. The switch looks to be available, but the bracket is not, at least online.

 

[Armymutt]

I pulled the wires off the alternator - no change. I then pulled the cable from the battery to the starter solenoid. I noticed that instead of going from a bright to dim light, the light just stayed dim. From what I can tell, that cable is the only thing directly attached to the battery. Does that mean the battery is self discharging?

 

[Bluox]

Have your battery checked .
Bob

 

[Delmer]

... Does that mean the battery is self discharging?

No, if there's current flowing through the test light, then the same current is flowing through the other battery post to the ground/chassis and back through the test light. Did you remove the big battery cable from the starter solenoid? No worry of big sparks unless you touch it to the other battery terminal, you're doing this with the test light between the negative terminal and the ground cable, right?

The only way that I know of to see if the battery is self discharging is to charge it up, remove one cable for a week, and see if it will still start or not.

 

[fpgm04]

I am going suggest going old-school here if you want to see if the battery is self discharging.

Use a battery hydrometer to test each cell. A cheap hydrometer from an auto store is only about $6. In that way you can see day-to-day if a battery is self discharging due to internal corrosion or cell plate damage. It will also tell you immediately if you have bad/weak cell which requires replacing the battery.

Even in today’s so called sealed batteries, the cells typically can still be accessed by prying up the caps.

Also, what is the date code on your battery? Is the battery rated for off-road? Many on-road automotive batteries now-a-days may not last very long bouncing around in a TLB.

Note: Need to follow Delmer's instructions to charge and disconnect battery, but with hydrometer, readings can be taken day-to-day.

 

[Armymutt]

I took the battery to Napa to have it checked. It was reading a bit low and the CCA were under what the label stated. It wasn't fully charged, but they gave me a free replacement - battery was purchased in July 2019. I installed the new one and have the same test light results as before. With the positive cable removed from the starter solenoid, I get a dim glow. Hook it up, and I get the same bright bulbs that quickly turns dim. I've got a battery disconnect kit on order. Hopefully it's in by the weekend.

 

[joeblow]

I had a similar problem with our Case.As hoes are often left on the street and since all the keys are the same they are very easy to steal.We found a GPS pinger in the thing that was only pulling .02 of an amp;enough to light a test lamp dimly but not to show on an amp meter.It would kill the battery in a week but not be a problem if it was your daily driver, If you want to isolate the circuit then l would leave the test light connected between the battery and the cable and pull the fuses out one by one. It will at least tell you where to start looking.

 

[Armymutt]

I had a similar problem with our Case.As hoes are often left on the street and since all the keys are the same they are very easy to steal.We found a GPS pinger in the thing that was only pulling .02 of an amp;enough to light a test lamp dimly but not to show on an amp meter.It would kill the battery in a week but not be a problem if it was your daily driver, If you want to isolate the circuit then l would leave the test light connected between the battery and the cable and pull the fuses out one by one. It will at least tell you where to start looking.

I did that last night, unless there are some fuses not located under the dash. I'm going to try removing the wire leaving the solenoid and hook the battery wire back up to it to see if I get the bright light again.

 

[fpgm04]

Let me ask a few questions to perhaps help locate the source of current draw.

Does the machine have any aftermarket accessories installed that were possibly spliced in the wiring outboard of the factory fuse panel? For example a radio, roof beacon, fan, power seat, etc?

I am not familiar specifically with a 310SG. Does it have an electronic engine controller? Many engine control systems have separate fusing, even going around a battery disconnect, to allow the controller to cleaning write memory during key-off shutdown.

Does the machine have a engine grid heater or glow plug cold start system? Many times those have separate higher current fusing and relays in the engine compartment along with associated controller.

 

[mg2361]

According to your serial number your machine has an ECU. Try disconnecting that. It would be located on the left side of the engine. It is normal for the ECU to momentarily draw enough to light a light, but then the light should go out. It would be better to use a digital meter set to the mA scale. With all this being said I mentioned earlier about relays. Did you disconnect the accessory relay. Not the ones "in" the fuse panel but the big "Ford" looking one next to the fuse panel?

 

[Armymutt]

According to your serial number your machine has an ECU. Try disconnecting that. It would be located on the left side of the engine. It is normal for the ECU to momentarily draw enough to light a light, but then the light should go out. It would be better to use a digital meter set to the mA scale. With all this being said I mentioned earlier about relays. Did you disconnect the accessory relay. Not the ones "in" the fuse panel but the big "Ford" looking one next to the fuse panel?

Would the ECU continuously draw enough to light the light? It's strange to me that there is something drawing that acts almost like a capacitor. When I touch the light to the battery, it is bright for a fraction of a second and then goes dim. If there is something removable under the dash panel, I removed it. There is another device that has wires bolted to it. It's cylindrical and not a push-in type. Lots of wires going to it.

The battery was dead when I went out to start it this afternoon. That's really concerning. I wonder if I had the ignition turned too far back when I shut it off last night. Doesn't account for the original issue, but being in the accessory position would kill the battery. It's on the slow charger. Maybe it'll be able to start in a couple of hours.

 

[joeblow]

The alternator is still hooked to the + battery terminal, if the diodes are leaking even a tiny bit, that will drain the battery over a week. Or the battery is discharging on it's own. I'd leave the charger on there for a day, then remove and leave the ground cable off the battery until you use it next time, then see if it starts or not. And then get a new battery, or look into the alternator more.

0.00 amps, I don't trust. The glowing test lamp, I trust. I suppose it's not that hard to remove the big b+ terminal wire at the alternator and see if the lamp goes out, if you don't want to wait.

The best way I have found to check for leaking diodes is to do a "ripple test". Attach your volt meter to the alternator with the engine running .Switch the volt meter to AC volts.If you find more than half a volt AC then your diodes are leaking.If you are replacing ECUs and CPUs it is a good test as they don't like AC voltage.

 

[doghead]

If you simply unhook the alternator and the drain is gone, Disassemble the alt to rebuild it and test the diode trio. The AC Delco diode trio is Usually less than 10 bucks, so I replace them anyways when rebuilding.

 

[joeblow]

If you simply unhook the alternator and the drain is gone, Disassemble the alt to rebuild it and test the diode trio. The AC Delco diode trio is Usually less than 10 bucks, so I replace them anyways when rebuilding.

As long as you get all those fibre washers in the right place otherwise you will let all the smoke out of it.

 

[Armymutt]

If you simply unhook the alternator and the drain is gone, Disassemble the alt to rebuild it and test the diode trio. The AC Delco diode trio is Usually less than 10 bucks, so I replace them anyways when rebuilding.

Disconnecting the alternator didn't do anything. I don't think it is the culprit. I got it charged enough to run it for about an hour tonight. I stopped it and it restarted with no problems. Going to try to find the test and repair manuals and see what I can find out.