Charging system on a 4010 Diesel.

All you have to doto find out for sure is put a voltmeter on the battery terminals. If the voltmeter reads about a volt more than battery voltage the alt is still charging.

Mine is OEM 24v system with 24v gen and regl. 2 batteries, 1 +, 1 - to chassis.

As Roy said, on mine, if you don"t excite it, it doesn"t produce. Excitement has to come through the ign switch as otherwise it would run the batteries down when engine is off.

Starter may be 12v (still OEM) cause with the batteries mounted right next to the starter (homemade batt box), (950CCA) and 00 gauge wiring less than 15" each, the sucker screams to life when you tell it to.

Mark

If so, then either 2 things I can think of are happening. 1) the starter is actually 24v and in good shape. 2) the right hand battery does nothing, at least it isn"t used during cranking.

I am assuming you have a pair of 12 volt batteries. I am curious what brand you have with 950 CCA? I just bought a pair of JD strong box"s for my 4020 and they are 650 CCA at 0 deg F.

Sounds like some strong batteries!

Batteries. Got them from an OTR (18 wheeler) dealership. Has a size 31 which is the size of a (boat"s trolling motor 27 size) but like a trolling batt, has studs instead of the lead posts. Also unlike the troll batt, it delivers lots of current on demand. Would bet that the starter sucks 300 amps when you smack it.

I am basing my assumption of the 12v starter on the fact that it spins so fast when I hit it. I know Ford used 6v starters on 12v systems for years. Maybe Deere did the same. If it"s important, I can scratch the paint off the nameplate and see if it defines the voltage. Since you are only on the starter for a short period, and there is a lot of mass (weight to get hot) it is not unrealistic to have a 12 v on a 24 system.

Besides, some tractors are parallel batteried 12v systems and they would have to build 2 different starters for that and (personal opinion) I doubt that.

My batteries are stacked in series with tractor ground being in the center (one + system, one - system) The gen goes across both with the 24 volts.

Mark

Thanks for the response! I thought about checking the parts web site to see if the 4020 gas and 4020 Diesel used the same starter part number. I dismissed that because even if they share the same guts doesn"t mean JD would give them the same part number. Other stuff might be different.

Rather than one batt wire going the starting solenoid (most starters) this starter has a second terminal on the side which is for the other battery.

It is a 24 volt starter. So a 12v conversion would have to address gen, vr, and starter. To say that you could do it with the same starter, I'd have to look at the schematic of the starter.

Sorry for the confusion.

Mark

"The 12 volt starter would have to be isolated from ground to spin it with 24 volts."

This is true with these tractors that use the chassis to connect or string the two batteries together. So from chassis to any battery post is either 0 volts or 12 volts.

Since the batteries are in series, they both have to be connected to work. Hence one switch (starting solenoid mounted on top) can suffice to operate the 2 batteries and one starter. Since the start/gen/reg loop is on 24 volts, it cares less about tractor chassis. Only the acc and lights are really hooked to that.... and it (the chassis) serves as the "link cable" mentioned in other similar posts back a couple of days.

One more thing. I broke my solenoid hooking up this "cable" (00 size wiring) and bought a replacement from Walts, via this web "tractor parts" inquiry. Seemed very knowledgeable. Maybe he can answer any questions you may have about what part number starter goes to what tractor.

Enjoyed yakin.

Mark

The 12 volt starter would have to be isolated from ground to spin it with 24 volts.