2655 Cab shuttle phantom current draw - Any ideas?

[OldTrix]

I have a 2019 2655 Cab shuttle with about 210 hrs on it. The tractor has been working great. On my last trip north (VT), I discovered the battery was dead flat, wouldn't accept a charge. I wrote it off to the cold weather and put in a new battery. Blew off the driveway and did some other timber work and parked it.

2 weeks later, I'm back up north and the same thing. The battery was flat and had obviously frozen. Another battery...

The tractor is charging, I get about 14.3/14.4 volts while running. Turn it off, and the voltage begins to trickle down slowly.

An ammeter between the battery and harness reveals about an .85A draw. I pulled every fuse in the panel under the instruments, no change. pulled the relays and 40/50a fuses next to the air cleaner. nada. Still the same parasitic draw.

I assume I have a harness chafing somewhere, unless I've missed a fuse or relay of which I'm not aware. Has anyone encountered this problem on this model? Any likely places to look first? I was thinking alternator, but the charging voltage looks OK, and I would suspect it would show other symptoms.

The shortstop fix is to disconnect the battery while it's idle. I'll begin chasing wires when it gets warmer outside.

Any ideas?

 

[3gunr]

My cub cadet always did that until i figured out it was a switch for the lights , It had to be in a certain position even with the lights off. My mahindra 2810 has a seperate kill knob and if you dont turn the key off it will kill the battery, My neighbor has done this to me several times after using it. How about a radio or cab lights that are staying on.

 

[duffer]

Could be any # of things. Cab accessories, ECU, an after market accessory you installed (if any), and on and on.

Easiest fix might be to install a battery disconnect switch. Almost all of the farmers have one on all their tractors. Especially with a cab, there just seems to be so many things that could cause the draw, along with what you outlined.

 

[OldTrix]

The radio is powered with the ignition, but I powered it down and removed the faceplate to be certain. Just weird, working fine one day, draining the batt the next. I'm more concerned there is a harness chafe somewhere, as that could turn ugly if it worsens while in use.

I guess I need to find a wiring diagram somehow so I can chase a few more possibilities. Anyone had any luck finding one?

 

[mwayne]

Have you checked for a bad diode on the alternator?

 

[5030]

If it has an ECM it's the ECM that is draining it. They require constant current and a minimum of I think 9.5 volts to stay alive. I'd be putting a tender on it or a solar powered maintainer.

Far as buying a new battery and dropping it in, bad idea. Always trickle charge a new battery for at least 12 hours before installing.

 

[OldTrix]

Have you checked for a bad diode on the alternator?

That is on the list to check. It seems unlikely, as the voltage looks good while running, but it could explain the current leak.

 

[OldTrix]

If it has an ECM it's the ECM that is draining it. They require constant current and a minimum of I think 9.5 volts to stay alive. I'd be putting a tender on it or a solar powered maintainer.

Far as buying a new battery and dropping it in, bad idea. Always trickle charge a new battery for at least 12 hours before installing.

I don't think the ECM requires nearly an amp of current to stay lit. Usually those draw milliamps. And why would it now suddenly start pulling that amount of power?

Yes, I charged the battery overnight before starting. Like I said, unexpected new issue, so I now unhook the battery and keep the tender on it while I'm gone.

 

[5030]

I don't think the ECM requires nearly an amp of current to stay lit. Usually those draw milliamps. And why would it now suddenly start pulling that amount of power?

Yes, I charged the battery overnight before starting. Like I said, unexpected new issue, so I now unhook the battery and keep the tender on it while I'm gone.

What I did with both of my pre 4 tractors when they sit in the barn is, I added a knife switch disconnect to the negative battery post that isolates the battery when not in use. Like 25 bucks at any auto store.

I think I'd use a multi meter and measure the current consumption the ECM is pulling to be sure.

 

[OldTrix]

When i get back up in a week or so, I plan to pull the ECM plug and note the difference in current draw. I'm also going to disconnect the alternator and see what happens. I'm leaning more toward a bad diode, but will need to confirm.